Transducer/flexure/conductor structure for electromagnetic read/write system

ABSTRACT

Flexure/transducer structure employable in an electromagnetic information storage and retrieval system wherein mechanical load-bearing responsibilities and electrical-current-carrying responsibilities are merged into and shared by common structure. The invention subject matter is useable in systems characterized by contact operation, as well as by quasi-contact and noncontact operations, in relation to the recording surface in an information recording medium.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This is a continuation application of U.S. patent applicationSer. No. 08/338,394 which was filed on Nov. 14, 1994, which is acontinuation-in-part of U.S. patent application Ser. No. 08/191,967 (nowabandoned) which was filed on Feb. 4, 1994, which was acontinuation-in-part of U.S. patent application Ser. No. 07/919,302 (nowabandoned) which was filed on Jul. 23, 1992, which was acontinuation-in-part of U.S. Pat. No. 5,174,012 which was filed on Dec.12, 1991 and issued on Dec. 29, 1992, which was a continuation of U.S.Pat. No. 5,073,242 which was filed on Jul. 24, 1991 and issued on Dec.17, 1991, which was a continuation of U.S. Pat. No. 5,041,932 which wasfiled on Nov. 27, 1989 and issued on Aug. 20, 1991. This is also acontinuation-in-part of U.S. patent application Ser. No. 07/990,005 (nowabandoned) filed Dec. 10, 1992 which is a continuation of U.S. patentapplication Ser. No. 07/746,916 (now abandoned) filed on Aug. 19, 1991.Additionally, this is a continuation-in-part of Ser. No. 07/966,095 nowissued as U.S. Pat. No. 5,550,691, which was filed on Oct. 22, 1992 andissued on Aug. 27, 1996 which is a continuation-in-part of U.S. patentapplication Ser. No. 07/783,509 (now abandoned) filed Oct. 28, 1991.Further, this is a continuation-in-part of U.S. patent application Ser.No. 07/783,619 now issued as U.S. Pat. No. 5,490,027 filed on Oct. 28,1991 and issued on Feb. 6, 1996. This is also a continuation-in-part ofU.S. patent application Ser. No. 08/179,758 (now abandoned) filed onJan. 7, 1994, which is a continuation of U.S. patent application Ser.No. 07/684,025 (now abandoned) filed on Apr. 10, 1991. This is also acontinuation-in-part of U.S. patent application Ser. No. 08/017,984 (nowabandoned) filed on Feb. 12, 1993, which is a continuation from U.S.patent application Ser. No. 07/770,593 (abandoned) filed on Oct. 3,1991. This is also a continuation-in-part from U.S. patent applicationSer. No. 08/180,540 (now abandoned) filed Jan. 12, 1994, which is acontinuation-in-part from U.S. patent application Ser. No. 07/760,586(now abandoned) filed Sep. 16, 1991. The following U.S. patentapplications and patents are incorporated by reference into thisapplication: application Ser. No. 07/911,680, U.S. Pat. No. 5,041,932,application Ser. No. 07/990,005, application Ser. No. 07/746,916,application Ser. No. 07/966,095, U.S. Pat. No. 5,550,691, applicationSer. No. 07/783,509, application Ser. No. 07/783,619, U.S. Pat. No.5,490,027, application Ser. No. 08/179,758, application Ser. No.07/684,025, application Ser. No. 08/017,984, and application Ser. No.07/770,593.

FIELD OF INVENTION

[0002] The present invention relates to electromagnetic read/write,information storage and retrieval systems, and in particular, to thestructural merging in such systems of electrical and mechanicalfunctionality, and to ancillary matters that surface as structural,organizational opportunities as a result of such merging. Recognizingthat the various features of the invention can have importantapplicability in a wide range of kinds of such systems (e.g.,rigid-disk, floppy-disk, drum, tape, etc. systems), the descriptionwhich follows herein focuses attention on rigid-disk systems—an arenawhich is most central in today's commercial applications. Accordingly,specification and claim references made herein to rigid disks should beread to include these other-kinds-of-media systems.

[0003] Given the merged-functionality aspect of the present invention,many features thereof, accordingly, focus upon improvements inmechanical load-bearing and in motion-articulating characteristics oftransducers, and of flexures which carry such transducers, that are usedin these kinds of systems. In this context, the field of the inventionencompasses systems wherein (a) a read/write transducer flies over amedia recording surface, (b) such a transducer is intended forcontact-capable operation, and operates with intermittent media-surfacecontact, and (c) such a transducer is intended for contact-capableoperation, and operates in substantially continuous contact with a mediarecording surface.

BACKGROUND AND SUMMARY OF THE INVENTION

[0004] In the march of progress which has characterized ongoingdevelopment of disk-drive, electromagnetic read/write systems, thequests for enlargement of areal recording density, and forimproved-quality read/write signal communication between a disk'srecording surface and a transducer, have been high on the list oftechnical interest and relentless pursuit. This situation has beenreflected, inter alia, in significant reductions in components' sizesand masses, by reductions in the “effective masses” of those componentswhich react dynamically during read/write operations, and in dramaticreduction in the separation which exists between the working read/writezone of a transducer and a disk's recording surface. These advancesinclude, according to an important line of development by the CenstorCorporation of San Jose, Calif., system embodiments in which aread/write transducer operates in substantially continuous slidingcontact with such a recording surface. The latter line of advancement inthe art of disk-drive recording is well illustrated and expressed in theparent patent and patent applications which have been set forthhereinabove.

[0005] Pausing for a moment at this point to focus upon prior artefforts by others to bring about size reductions, it is important tobear in mind that these prior art changes have, by and large, beenaccomplished with what might be thought of as a segregated rather than amerged focus upon the three core functionalities—electrical, mechanicaland magnetic—of read/write transducers and supporting flexures. In otherwords, prior art thinking has looked upon the respective components inthis environment which offer each of the individual functionalities asbeing essentially independent of the other-functionality components. Asa consequence, there has been somewhat of a naturally perceived limit inhow far one can go to bring about significant size reduction—a limitdictated by functional performance constraints, and even moreappreciably, probably, by manufacturing-costs andmanufacturing-capabilities constraints.

[0006] Specifically, and looking for a moment just at the issue ofmechanical load bearing, prior art thinking has been based upon thenotion that once necessary mechanical load-bearing requirements areknown, all of that structure which has been looked upon in the past asbeing the sole constituent attending to that functionality can only bereduced in size just so much if it is to remain practicallymanufacturable. However, beginning with the work of Hal Hamilton as suchis expressed in the above-referred-to '932 patent, a new kind ofthinking has entered this art, whereby “merger of functionality” isviewed as providing an opportunity for retaining all necessaryelectrical, mechanical and magnetic capability, while at the same timeallowing for substantial shrinking of overall size, and actualimprovement in practical manufacturability. More particularly, in theHamilton '932 disclosure, there surfaces a recognition that electricalcurrent-carrying structure can be utilized significantly to carrymechanical load, and conversely, that mechanical load-bearing structurecan be utilized significantly to carry electrical current. In otherwords, what might be thought of as singular-character structure, ormaterial, functions in multiple ways. Not only does this unique way ofthinking about merged-functionality yield surprising size- andmass-reduction opportunities, but also it tends to lead towardstructures which are inherently simpler in form and in construction, andless complex and costly to fabricate.

[0007] It is this “merged-functionality” view which underlies keycontributions made to the art by the present invention.

[0008] Continuing, and directing attention to other matters upon whichthis invention is focussed, in the ever more intimate environment of theinterface between a disk's recording surface and a read/writetransducer, and in addition to the size, mass, effective mass andspacing issues just generally expressed, many other considerations sitas important participants at the table of key technical concerns. Forexample, tight control over, and maintenance of, a very precise XYZspatial location of a transducer in relation to a disk surface iscritical, as is the ability of the transducer and supporting flexurestructure to respond rapidly and fluidly to disk-surface topographicalfeatures, and/or to other things and events which require speedy,accommodating, operating-attitude adjustment. This kind of adjustmentmust take place in a manner minimizing as much as possible any occasionsof signal-communication drop-out, and in a manner free of disruptiveresonance vibrations. Attention also must be addressed to damping andshock-absorbing issues.

[0009] All of these considerations need to be taken into account as well(a) in systems where a transducer flies over a disk's recording surface,(b) in systems where contact operation occurs (intermittently orcontinuously), and (c) in systems which, on the one hand, have gimbaledtransducer structures, and on the other hand, non-gimbaled transducerstructures.

[0010] In the gimbaled transducer setting, the merged functionalityfocus aspect of the invention opens the door to the fabrication and useof a load-bearing transducer chip which has a substantially planar body,with plural, projecting disk-surface contact feet, or pads, and whichcan operate, relative to a disk's recording surface, with substantiallya zero-angle-of-attack, and with the read/write portion of thetransducer in intimate contact with that surface. This, in turn, offersthe opportunity for electromagnetic design which occupies space in theplane of the body, and which allows for placement of the read/write zoneanywhere relative to that body.

[0011] Given the above remarks and comments, it is an important objectof the present invention to offer transducer/flexure improvements alongthe lines just suggested—focused on the notion of structural merging,for example, of electrical and mechanical functionality.

[0012] A related object of the invention is to provide such improvementswhich lead toward simple, low-cost, low-mass structures that offer theopportunity for appreciable enlargement in areal density of recordedinformation, with reliable and improved signal-communicationcharacteristics.

[0013] Thus, an important object is to provide a head/flexure structurewhich includes load-bearing (merged-functionality) conductors.

[0014] A related object is to provide a head/flexure structure in whichthe conductors perform mechanical functions in addition to theirfunction of conducting electrical signals between a head and othercircuitry.

[0015] Still another object of the invention disclosed herein is toprovide a flexure/conductor structure which supports a head in a preciselocation and orientation relative to the surface of a medium.

[0016] Yet a further invention object is for the head-supporting flexureto be capable of supporting the head in a contacting relationship withthe disk while reading or writing, without the occurrence ofcatastrophic head crash events or excessive interface wear.

[0017] Also, an object of the invention is to provide aflexure/conductor structure which is capable of moving, the head along aZ-axis, i.e., that axis which is normal to the surface of the disk, witha minimal degree of angular rotation, i.e., minimizing the angularconstant.

[0018] Another object is to provide a flexure/conductor structure whichexhibits maximum levels of lateral and torsional resonant frequencieswith the minimal amount of gain.

[0019] Still a further object is to provide atransducer/flexure/conductor structure which has a minimal number ofparts, and which can be produced by a relatively straight-forward andcost-effective process, including, in certain cases, an automatedassembly process.

[0020] Another object is to provide a flexure/conductor structure whichis capable of compensating for topographical irregularities in thesurface of the recording medium.

[0021] Yet another object of the invention is to provide aflexure/conductor structure in which the head is allowed a certain rangeof pitch and roll movement independent from the flexure.

[0022] A further object is to provide a head/flexure structure which hasa tunable hinge near its proximal end.

[0023] Other objects include providing a head/flexure structure which:(a) is wireless; (b) is amenable to compact disk-to-disk stacking; and(c) contains more than one pair of conductors.

[0024] Still a further object is to provide a head/flexure structurewhich has a gimbal including conductive articulators.

[0025] Thus, the inventive subject matter presented herein regardsimprovements in transducer/flexure structure for an electromagneticread/write system, and relates, inter alia, to structures, such asflexures, for carrying electromagnetic read/write transducers, and moreparticularly, to such structures wherein electrical conductors whichconnect with such transducers are utilized significantly, in anaugmentive way, as mechanical load-bearing and articulating elements inthe structures. The subject matter of the invention also relates tocontact-capable read/write systems in which the read/write transduceracts directly as a load-bearing structure under disk-contact conditions.According to an important aspect of the invention, therefore, suchaugmented-role conductors play the dual roles of (a) conductingelectrical signals between a transducer and remote, external circuitry,such as a signal processor, and (b) at the same time supportingmechanical load (such as a bending and/or articulating load), including,in certain embodiments, 100% of that load in a certain portion or regionof a transducer-carrying structure.

[0026] Fundamentally, the subject matter of the present invention restson several key concepts, some of which spring from the notion thatinnovation in the load-carrying/articulation characteristics oftransducer-carrying structure can significantly enhance overallread/write system performance. One of these concepts—based upon a newand striking “merged-functionality” recognition—is that the very sameconductors which carry signal-bearing information to and from aread/write transducer can also function mechanically as the articulatingand load-bearing beam structure which carries and supports such atransducer, statically and dynamically, for instance, in the setting ofa cantilever-type support arrangement for a disk read/write transducer.This conceptual thought carries also into an arrangement where,effectively, the transducer is supported for gimbaling action, with therecognition that what might be thought of as the gimbal articulators(hinges or torsional beams) can be formed by electrical-current-carryingconductors.

[0027] Another foundation concept is that the flexure/beamtransducer-carrying construction can take important advantage of whatcan be viewed as bilateral motion independence, wherein a pair of spacedbeam components afford a single- or dual-axis articulation capability toa supported transducer. Indeed, such construction can enabledual-degree-of-motion gimbal action (as just suggested above) for such atransducer. The shift of mechanical articulation and load-bearingresponsibilities to signal-carrying conductors is an especially usefulconcept in so-called micro-flexure designs where extremely smallmechanical structures are involved.

[0028] A further important concept is that a read/write transducer canitself be utilized as a load-bearing structure—a concept leading, interalia, toward minimizing of the size and mass of the overalltransducer/flexure/conductor structure.

[0029] In addition to the structural contributions made by the presentinventive subject matter, also furnished thereby are novel methods ofproducing micro-transducer-support structures employing signal-carryingconductors as mechanical load-bearing/articulating elements such, forexample, as hinges, torsional beams, etc.

[0030] These and other objects, advantages and features that are offeredby the present invention will become more fully apparent as thedescription which now follows is read in conjunction with theaccompanying drawings.

DESCRIPTION OF THE DRAWINGS

[0031]FIGS. 1A and 1B are views of a transducer/flexure which isdisclosed and claimed in U.S. Pat. No. 5,041,932. FIG. 1A is a side viewof the transducer/flexure, loaded on a disk, in relation to an XYZcoordinate system. FIG. 1B is a cross-sectional view of the flexureshown in FIG. 1A, with this view being taken generally along line 1B-1Bin FIG. 1A.

[0032]FIG. 2 is an exploded perspective view of a taperedtransducer/flexure structure with load-bearing conductors and a hinge.

[0033]FIG. 3A is a top view of the transducer/flexure shown in FIG. 2.

[0034]FIG. 3B is a partial side view of the distal end of thetransducer/flexure shown in FIG. 3A.

[0035]FIG. 3C is a bottom view of the transducer chip shown in FIG. 3B.

[0036]FIG. 3D is an enlarged, fragmentary view of the area in FIG. 3Bembraced by curved arrows 3D-3D, illustrating a modified form oftransducer pole and coil structure.

[0037]FIG. 4 is a partial top view of a flexure, focusing on the hingeregion.

[0038]FIG. 5A is a cross-sectional view of the flexure shown in FIG. 3A.

[0039]FIGS. 5B and 5C are cross-sectional views of flexures withload-bearing conductors and additional damping and constraining layers.

[0040]FIG. 6 is a partial side view of the flexure shown in FIG. 3A,focusing on the hinge region.

[0041]FIG. 7 is a schematic partial view of a flexed beam with anintervening adhesive resin layer.

[0042]FIG. 8 is an exploded perspective view of a transducer/flexurewith four conductors, and a hinge near the proximal end of the flexure.

[0043]FIG. 9 is a top view of the transducer/flexure shown in FIG. 8,assembled. Conductor boundaries, which are covered by stiffeners, areindicated by dashed lines.

[0044]FIG. 10 is an exploded perspective view of a transducer/flexurewith load-bearing conductors and a load-button gimbal.

[0045]FIG. 11 is a perspective view of the transducer/flexure shown inFIG. 10, assembled except for mounting of the chip (transducer).

[0046]FIG. 12A is a top view of the transducer/flexure shown in FIGS. 10and 11. Conductor boundaries, which are covered by stiffeners, areindicated by dashed lines.

[0047]FIG. 12B is a partial side view of the distal end of the flexureshown in FIG. 12A.

[0048]FIG. 12C is a bottom view of the transducer shown in FIG. 12B.

[0049]FIG. 13 is an exploded perspective view of a transducer/flexurewith load-bearing conductors, a hinge near the proximal end of theflexure and a gimbal near the distal end of the flexure.

[0050]FIG. 14 is a partial top view of the conductors shown in FIG. 13,focusing on the distal ends of the conductors, specifically, theconductor gimbaling structure.

[0051]FIG. 15A is a top view of the transducer/flexure shown in FIG. 13,assembled.

[0052]FIG. 15B is a partial side view of the transducer/flexure shown inFIG. 15A.

[0053]FIG. 15C is a bottom view of the transducer shown in FIG. 15B.

[0054]FIG. 15D is a partial side view of the distal end of a gimbaledtransducer/flexure with a modified transducer and pad configuration.

[0055]FIG. 15E is a bottom view of the transducer shown in FIG. 15D.

[0056]FIG. 16 is a thin-layer sectional view of the flexure shown inFIG. 15A.

[0057]FIG. 17A is a partial top view of the distal end of thetransducer/flexure shown in FIG. 15A, with the addition of a membranedamping layer in the vicinity of the gimbal.

[0058]FIG. 17B is the same as FIG. 17A except the damping layer islocalized over four discrete regions of the gimbal.

[0059]FIG. 18 is a partial top view of the distal end of atransducer/flexure with a membrane which functions primarily as a gimbalstructure.

[0060]FIG. 19A is a top view of a transducer/flexure with load-bearingconductors, two hinges and a modified gimbal.

[0061]FIG. 19B is a partial top view of the distal ends of theconductors in the transducer/flexure shown in FIG. 19A.

[0062]FIG. 20 is a side view of the transducer/flexure shown in FIG.19A, operating on a disk.

[0063]FIG. 21 is a top view of a transducer/flexure, similar to the oneshown in FIG. 19A, except that conductor dimensions are modified.

[0064]FIG. 22A is a side view of the transducer/flexure shown in FIG.21, with a pre-bend near the proximal end of the flexure. The flexure isshown in its pre-loaded position (solid lines) and in its operating orloaded position (dash-dot lines).

[0065]FIG. 22B is a partial top view of a flexure which is similar tothe flexure shown in FIG. 21, except that it employs a modified gimbal.

[0066] FIGS. 23-25 are top views of modified two-conductor gimbalingstructures.

[0067]FIG. 26 is a top view of a modified four-conductor gimbalingstructure.

[0068]FIG. 27A is a partial top view of a two-conductor gimbalingstructure that forms part of a transducer/flexure which employs hingesto allow roll and pitch movement of the chip.

[0069]FIG. 27B is a partial top view of the gimbaling structure shown inFIG. 27A, with the addition of stiffening layers.

[0070]FIG. 28A is a top view of a first embodiment of a torsionallycompliant transducer/flexure.

[0071]FIG. 28B is a side view of the transducer/flexure shown in FIG.28A.

[0072]FIG. 29A is an exploded perspective view of a second embodiment ofa torsionally compliant transducer/flexure, with a pitch gimbalmechanism.

[0073]FIG. 29B is a top view of the transducer/flexure shown in FIG.29A.

[0074]FIG. 30 is a top view of a third embodiment of a torsionallycompliant transducer/flexure with a pitch gimbal.

[0075]FIG. 31 is an exploded perspective view of a dual-cantilevertransducer/flexure with four conductors and four hinges.

[0076]FIG. 32 is a perspective view of the transducer/flexure shown inFIG. 31, assembled.

[0077]FIG. 33 is a side view of the transducer/flexure shown in FIGS. 31and 32. The flexure is shown in its pre-bent unloaded position (solidlines), and in its loaded or operating position (dash-dot lines).

[0078]FIG. 34A is an exploded perspective view of anotherdual-cantilever transducer/flexure.

[0079]FIG. 34B illustrates the transducer/flexure of FIG. 34A,assembled.

[0080]FIG. 34C is a schematic side view of the transducer/flexure shownin FIGS. 34A and 34B, in its unloaded position (dash-dot lines) andoperating position (solid lines).

[0081]FIG. 35 is an exploded perspective view of anothertransducer/flexure embodiment.

[0082]FIG. 36A is an exploded perspective view of still anotherdual-cantilever transducer/flexure embodiment.

[0083]FIG. 36B is a partial side view of the distal end of thetransducer/flexure shown in FIG. 36A.

[0084]FIG. 37A is a schematic side view of a disk-contacting mountconfiguration supporting a transducer/flexure in its operating position.

[0085] Each of FIGS. 37B and 37C is a top view of a transducer/flexureof the present invention including an alternative gimbal design.

[0086]FIG. 38A is a schematic side view of a flexure mounting systemshowing disk-to-disk spacing with respect to an E-block and mountedflexures.

[0087]FIG. 38B is a schematic side view of a modified flexure mountingsystem employing dual-cantilevers to permit closer disk-to-disk spacing.

[0088]FIG. 38C is a partial side close-up view of one of the flexuresand dual-cantilever mount structures shown in FIG. 38B.

[0089]FIG. 39A is a schematic top view of a transducer/flexure mountedon a nut plate and including a two-conductor configuration withversatile, redundant connective tabs on opposite sides with the proximalend of the flexure/nut-plate structure.

[0090]FIG. 39B is a schematic side view of four flexure/nut-platestructures as shown in FIG. 39A, mounted in an E-block and electricallyconnected to a flex cable.

[0091]FIG. 39C is a schematic top view of another nut-plate/flexureembodiment with versatile, redundant connector conductor tabs.

[0092]FIG. 40A is a top view of a gimbaled flexure embodiment which isdimensioned to operate under a minimal load.

[0093]FIG. 40B is a top view of the conductor configuration employed inthe flexure shown in FIG. 40A.

[0094]FIG. 40C is an enlarged partial top view of the flexure shown inFIG. 40A.

[0095]FIG. 40D is a schematic side view of a transducer/flexure with apre-bend near its distal end.

[0096] FIGS. 41-45 are schematic top view layouts of sheet intermediatematerials used in a production method of the present invention.

[0097]FIG. 46 is a top view of a flexure resulting from the processillustrated in FIGS. 41-45. Relative dimensions of the final flexurestructure are shown.

[0098] FIGS. 47-49 are schematic top view layouts of sheet intermediatematerials used in another production method of the present invention.

[0099]FIGS. 50A and 50B show working-side views of two modified forms oftransducer chips.

DEFINITIONS

[0100] Terminology in the specification and claims should be interpretedin accordance with the following definitions.

[0101] A “flexure” is a flexible cantilever beam, with or without gimbalstructure, for supporting a transducer adjacent a medium. A “suspension”may refer to a flexure, either alone or together with a flexure mountingsystem.

[0102] A “transducer” is an electromagnetic working organization, orunit, employed typically near the distal end of a flexure directlyadjacent a medium in a read/write system. The transducer includes poleand coil substructures and the embedding material surrounding thesubstructures. A pole has a read/write working region. As used herein,the transducer does not include ancillary joined structure such as airbearing rails in a conventional flying slider. In at least oneembodiment of the invention, the transducer is provided as an integratedcomponent of the flexure. In other embodiments, the transducer is in theform of a chip which is joined to the distal end of the flexure. Eachtransducer has a working side which faces the recording surface in amagnetic medium during normal read/write operations.

[0103] At various locations throughout this specification reference ismade selectively to the top and bottom sides of different structures.Where these terms are applied to a disk surface, it is assumed that therelated disk is operating in a horizontal plane. Where these terms areapplied to flexure, beam, transducer structures inside of thetransducer, and top side refers to the opposite side.

[0104] The “Z-axis” is perpendicular to the surface of a recordingmedium and extends vertically through a transducer mounted on the freeend of a flexure. A limited range of movement of the transducer alongthe Z-axis is allowed, as the transducer follows disk surfacetopography, during and between reading and writing activity. An “X-axis”and a “Y-axis” share a common origin with the Z-axis at the center ofthe distal edge of the transducer, and are perpendicular to each otherin a plane which is co-planar with the upper-most surface of the mediumwhen the transducer is operating in contact with this surface. TheY-axis is generally “longitudinal”, i.e., parallel to the length of theflexure. The X-axis is generally “lateral”, i.e., parallel to the widthof the flexure. The X, Y and Z axes are illustrated in FIG. 1A relativeto the distal tip of a transducer/flexure 60. The point of contact 62between the transducer and disk 64 coincides with the origin of thecoordinate system.

[0105] “Roll”, “pitch” and “yaw” refer to particular types ofinclinational movement of a transducer relative to its static oridealized suspended position adjacent the surface of a medium. “Roll”refers to rotational movement about the Y-axis of a transducer adjacentthe surface of a recording medium. “Pitch” refers to rotational movementaround the X-axis of a transducer adjacent the surface of a recordingmedium. “Yaw” refers to rotation around the Z-axis of a transduceradjacent the surface of a recording medium.

[0106] “Load-bearing” is defined and used, inter alia, in the context ofa cantilever flexure which has a mounting end and a free end extendinggenerally horizontally over (adjacent) the surface (upper or lower) of arecording medium, for example, a rigid disk. The free end of the flexuresupports and positions a transducer for reading and writing informationon the surface of a medium. By deflection, the free end (distal end) ofthe flexure is applied by a force (load) against either the surface ofthe medium or an air-bearing directly on top of the surface. Elements ofthe flexure which provide significant support for the load, i.e.,maintenance of desired Z-axis position of the transducer, are referredto as “load-bearing” structures. “Load-bearing” also relates to“articulation” (defined below) structure.

[0107] A “beam” is a transverse structural member which provides partialor complete support for a transducer adjacent the surface of a recordingmedium. The term “beam” may be used referring to the entire flexurebody, or a load-bearing component of the body.

[0108] “Anisometric” means inequality of measurements or properties. Thetern is used in this application with reference to a beam'saxis-differentiated bending stiffness—i.e., regarding a beam having apreferential bending axis.

[0109] “Articulation” is used with respect to two structural members(sometimes referred to as “arms”) which are linked together, but alloweda certain degree of movement relative to each other. An “articulator” isa semi-rigid structure connecting first and second parts, which permitsa selected range and type of mechanical movement of the parts relativeto each other. An “articulating conductor” is an electrical conductorwhich also functions as an articulator. A “hinge articulator”, alsoreferred to as a “beam/articulator structure”, is an articulator (unit,element) which bends around an axis perpendicular to a line centrallyand directly connecting the two parts (also referred to as a“longitudinal axis”). A “torsional articulator” is an articulator (unit,element) which twists around an axis centrally and directly connectingthe two parts (longitudinal axis). A “torsional beam” is a torsionalarticulator. A “mixed-mode articulator” (unit, element) is a hybrid of ahinge articulator and a torsional articulator.

[0110] “Hinge” is a connector between two parts which allows a degree ofmovement, i.e., bending, of the parts relative to each other.

[0111] “Proximal” is used to refer to the end vicinity of a flexurewhich is structurally anchored or secured to a read/write system frameor servo-control actuator. The proximal end of the flexure is alsoreferred to as the “mounting end”.

[0112] “Distal” is used to refer to the end vicinity of the flexurewhich carries the transducer and is also referred to as the “free end”.

[0113] “Angular constant” is defined, relative to a cantilever flexure,as the degree of angular change at the distal tip of the flexure for agiven deflection.

[0114] A “pad” (also referred to as an island) projects from a side orface of a flexure or a transducer chip and contacts the surface of adisk when the transducer/flexure is operating to read or writeinformation from the disk. With respect to flexures which employgimbals, a triangular organization of three pads is sometimes used, andreferred to as a “tri-pad” or “trident” structure.

DETAILED DESCRIPTION OF INVENTION

[0115] The invention, resting strongly on the merged-functionalityconcept set forth above, involves load-bearing and articulatingstructures for use in suspensions relating to micro-flexures whichsupport transducers in electromagnetic read/write systems. Thesestructures take the forms of load-bearing conductors and transducers,hinge-like mechanisms, torsional beams, and flexure mounting systemswhich allow production and implementation of flexures with low angularconstants, minimum mounting tolerances, and/or the capability oftolerant compliance of the transducer with an inherently irregularrecording medium surface. An important aspect of some of thetransducer/flexures disclosed and claimed in the present invention isthe use of electrical conductors and transducers which are geometricallydesigned and arranged to provide load-bearing support, as well asarticulable movement, between linked portions of the flexure body.

[0116]FIGS. 1A and 1B illustrate a micro-flexure 60(flexure/conductor/transducer structure), including an integratedtransducer, or transducer unit, which was originally described andclaimed in parent U.S. Pat. No. 5,041,932. The transducer, which is atiny portion of the overall structure pictured in FIG. 1A, is located atthe distal tip shown at 62. This transducer includes magnetic polestructure and coil and conductor structure all embedded in a smallvolume of surrounding joinder structure. It is in the disclosure of the'932 patent that the notion of merged-functionality makes its importantdebut in the read/write, disk drive transducer/flexure context. It isalso in the '932 patent that one finds the introduction of aload-bearing transducer unit. Reference to the text and drawings of thepatent will reveal a novel transducer unit having pole structure unifiedwith (and within) a disk-contacting wear pad (or projection), andgenerally planarly distributed, coupled coil structure which extendsgenerally in a plane parallel with the plane of the wear pad'sdisk-contacting face.

[0117] As shown in FIGS. 1A and 1B, micro-transducer/flexure 60 includesintegrated load-bearing conductors 61 a and 61 b embedded within flexure60 along its entire length (continuum structure). An integratedtransducer is embedded within flexure 60 at its distal tip 62 where itcontacts disk 64 during operation of the read/write system. A number ofimportant features of the present invention, which are more extensivelydeveloped in the embodiments illustrated and described below, are fullypresent in the micro-transducer/flexure structure illustrated in FIGS.1A and 1B. First, as shown in FIG. 1B, integrated conductors/beams 61 aand 61 b are massive enough relative to the entire flexure body 60 tosupport a significant portion of the cantilever load. According to theteachings of the '932 patent, conductors 61 a, 61 b occupy in the rangeof about 13% to about 40% of the full thickness of the body of flexure60. Therefore, conductors 61 a and 61 b play a dominant mechanical role,and are referred to as “load-bearing conductors”. Another importantphysical attribute of conductors/beams 61 a and 61 b is their generallyrectangular or “blade-like” cross-sectional shape which providespreferential (anisometric) bending, allowing the tip to move in adirection along the Z-axis. The blade-like shapes of conductors 61 a and61 b are also contributors to a relatively high lateral-frequencycharacteristic for flexure 60. Still another interesting geometricfeature of conductors 61 a and 61 b is their symmetrical organizationabout plane W which bisects flexure 60 along its length. Between theiropposite sets of ends, these conductors are also referred to assubstructure spans.

[0118] A second important load-bearing structure embodied in thetransducer/flexure of FIG. 1A, as briefly mentioned earlier, is thetransducer itself (the embedded pole structure and coil and conductorstructure mentioned earlier) located at the distal tip of flexure 60.Unlike flexures/transducers in the prior art, such as transducers joinedto massive load-bearing, sliders, in which the transducer carriesessentially none of the deflected beam load, the transducer integratedin the distal tip of flexure 60 directly contacts disk 64 and carries100% of the cantilever load—i.e., directly through the embedded pole,coil, and conductor structure. The uses of load-bearing conductors and aload-bearing transducer in a transducer/flexure device, provide examplesof a major theme of the present invention, namely, to designmulti-functional (i.e., merged-functionality) components so thatstructures, such as conductors and transducers, which traditionally havehad no mechanical function in prior art devices, become “mechanicalactivists” in the present invention, in addition to playing theirtraditional roles of conducting electrical signals and handling magneticflux.

[0119] A related micro-flexure structure 70 with load-bearingconductors, or conductor elements, and a proximal hinge, or hingeregion, is illustrated in FIG. 2. Micro-flexure 70 includes two,relatively flat, blade-like conductors (continuum structure) 72 and 74.Conductors 72 and 74, which form a common conductive layer, areinsulated from each other by space 75. Conductors 72 and 74,collectively, have a tapered shape, and are widest at proximal(mounting) end 76 and narrowest at distal (free, disk-confronting,transducer-carrying) end 78. End 76 is also referred to herein as a baseregion. A proximal stiffener layer, or stiffener, 80 overlays theproximal ends 76 of conductors 72 and 74. Stiffener 80 has a hole 82centrally located above a hole 84 defined by conductors 72 and 74. Holes82 and 84 are used for alignment of the suspension to a mounting surfacein a disk-drive system. A rectangular window 86 in stiffener 80 providesaccess to the top sides of conductors 72 and 74 for electrical bonding.Distal and proximal bonding regions of conductors 72 and 74 arepreferably gold plated. A second stiffener 88 extends from a “hingeregion” 89 near the proximal end of the flexure, to the distal end ofthe flexure. Hinge region 89, defined by the gap between stiffeners 80and 88, is shown more completely in FIG. 3A, FIG. 4 and FIG. 6. Thestructural regions located longitudinally on opposite sides of the gapare also referred to herein as arms. Four windows 90 in stiffener 88provide access to the conductors for heating them in the process ofconnecting a transducer chip 92 to the bottom side of conductors 72 and74. Chip 92 contains, for example, a probe-type read/write transducer(not illustrated), the probe in which extends toward the disk'srecording surface through a single, projecting contact (wear) pad, orprojection, 97 (see FIG. 3B).

[0120] A top view of flexure 70 is illustrated in FIG. 3A. Conductors 72and 74 are seen in hinge region 89 where they are separated by a gap 75.In addition to being tapered from hinge region 89 to the distal end offlexure 70, lateral edges 94 a and 94 b in the flexure are slightlyconcave—a design feature which has been found to yield improved (higher)torsional frequency characteristics.

[0121] Hinge region 89 of flexure 70 has the following preferredspecifications. Conductors 72 and 74 and stiffeners 80 and 88 aretype-302 (or type-304) stainless steel. The thickness of the hingematerial, i.e., conductors 72 and 74, is 0.5-mils. (1 mil.={fraction(1/1000)}-of-an-inch). The length of the hinge is 24-mils. Thesedimensions were selected for the purpose of maintaining a springconstant of approximately 2.5-mgs.-per-mil. Stiffeners 80 and 88 are1-mil. thick. Thus, most of the bending which occurs when the flexure isdeflected, occurs in hinge region 89.

[0122] The hinge design just described provides a number of importantbenefits. First, a lower angular constant is achieved relative to anon-hinged design. Optimal angular constant for a simple cantilever,such as the one illustrated in FIGS. 2 and 3A, is achieved when all thebending occurs at the base (i.e., a perfect hinge). In the flexure shownin FIGS. 2 and 3A, most of the bending occurs in the base 7% of thebeam. This results in an angular constant of approximately0.19°-per-mil. of deflection. Second, the hinge provides dampingcapability. Since most of the flexure is rigid, constrained-layer(electrically insulating) damping material, as illustrated in FIGS. 5A,5B and 5C (discussed in detail below), can be added to the stiffenedregion without affecting the spring constant. The damping material canbe positioned between the conductor and stiffener layers, and/or anotherset of damping and constraining layers can be added above or below theflexure if necessary to attenuate vibrational amplitudes. Third, thehinge provides improved drive tolerances. If a pre-bend is added to thehinge area of the flexure, the suspension can operate essentiallyflat—thus requiring less mounting space. This allows very closedisk-to-disk spacing. Structures, considerations and benefits relatingto the concepts of pre-bent flexures and disk-to-disk spacing will bemore fully developed below.

[0123] The trapezoidal/concave edge shape of the flexure, overall beamthickness, and 350-mil. free beam length provide the followingadvantages. First, the shape provides good lateral stiffness. Lateralstiffness increases as the cube of width. High lateral stiffness isdesirable for minimizing lateral vibrational movement. Second, bytapering the width at the tip, high lateral frequencies are achievedwhich are desirable for servo stability. Third, the “bugle” orconcave-edge shape was found to have the highest torsional frequency oftrapezoidal-like shapes. High torsional frequency is desirable for servostability because there can be a significant off-track motion associatedwith the torsional mode. Fourth, the design has been found to avoidundesirable modal interactions. We have discovered that certain normalmodes of vibration interact with others, causing high vibrationalamplitudes. Such interaction is caused by frictional changes at thetransducer/disk interface with contact pad angle changes. Accordingly,the following situations should be avoided: (1) lateral frequency 1×, 2×or 3× the torsional frequency, and (2) torsional or lateral frequency of1× or 2× any first or second bending frequency.

[0124]FIG. 3B is a side view of the distal end of flexure 70,illustrating the mounting of transducer chip 92 on flexure 70. Stiffener88 is separated from conductor 72 by an adhesive (bonding) layer 95.Solder structures, plus adhesive and/or conductive epoxy structures insome cases, such as the solder structures shown at 96 a and 96 b,electrically and mechanically connect conductor 72 to chip 92. Fullmechanical load is transmitted through these connections. Single pad 97is preferably made of amorphous diamond-like carbon (DLC), and ispositioned on the bottom side (in FIG. 3B) of chip 92, near the centerof its trailing edge, as shown in FIG. 3C. When transducer/flexure 70 isin its operating mode, pad 97 contacts the uppermost surface of disk(medium) 98. The single-pad configuration which is employed intransducer/flexure 70 and illustrated in FIGS. 3B and 3C ischaracteristic of the flexures shown in FIGS. 1-9, which do not includegimbals. When a single pad is employed in a non-gimbaled flexure, facetsare polished around the pad to provide full transducer signal through arange of static mounting tolerance. Other pad configurations andconsiderations are discussed below. Similar to the integratedtransducer/flexure structure shown in FIGS. 1A and 1B, transducer chip92, as shown in FIG. 3B, bears the entire cantilever load of thedeflected beam. Thus, the need for a separate load-bearing structure isavoided.

[0125] In the configuration shown in FIG. 3B, chip 92 containstransducer pole structure and coupled coil structure organized anddistributed in the following fashion. The read/write working portion ofthe pole structure extends within pad 97 to the bottom (in FIG. 3)disk-contacting face of the pad. The coupled coil structure occupies thegenerally horizontal (in FIG. 3) plane of the main body of the chip.

[0126] Shifting focus briefly onto the modification shown in FIG. 3D,here chip 92 contains pole structure and coil structure organized anddistributed in a somewhat different manner. Specifically, here, both ofthese structures occupy a plane which extends generally normal to thelong axis of flexure 70. This planar region is indicated generally at99. Here too the read/write working portion of the pole structureextends within pad 97 to the bottom face of the pad. This organizationis referred to as a “pin head” type arrangement.

[0127] The FIG. 3D embodiment suggests the possibility of creating yetanother kind of transducer chip which is fully planar, and intended forsuitable mounting at the end of a beam/flexure, in a disposition withits plane, including the plane of the body of the chip, normal to thelong axis of the beam/flexure. Such a situation is specificallyillustrated and described in a portion of this specification set forthbelow. In all cases the transducer is load-bearing.

[0128] The performance or flexibility of the hinge region can bemodified or tuned by, for example, altering the dimensions of theconductors in the hinge region, or by changing the width of the gapbetween stiffeners, as illustrated in FIG. 4. Here, for example, anillustrated hinge 100 includes conductor portions 102 and 104 flanked bystiffeners 105 and 106. Flexibility of conductor portions 102 and 104 inthe hinge region can be altered or tuned by changing the gap width. Forexample, if the hinge gap edge is relocated to line 109, then hingeflexibility is increased. Similarly, other changes in conductor geometryor material composition provide different ways of tuning the hinge.

[0129]FIG. 5A shows a cross section of flexure 70 as illustrated in FIG.3A. Conductors 72 and 74 are separated by air gap 75, and are bound tostiffener 88 via adhesive layer 95 (a resin). Stiffener 88 and layer 95collaboratively form joinder structure for the conductors. Importantly,resin 95 functions to insulate conductors 72 and 74 electrically fromstiffener 88. Stiffening and/or vibrational damping can be enhanced byselecting an appropriate type, amount and application of the adhesiveresin. Adhesive layer 95 is preferably 1.0-mil. thick. Adhesive resinswhich have been used to bond conductor and stiffening layers in laminantflexures of the present invention include epoxies, acrylics andpolyimides in both liquid and sheet forms. For example a liquid epoxyresin available from Bondline, referred to as 6555™, can be used in thepresent invention. An epoxy resin in sheet form is available from AITechnology, referred to as TK7755™. An acrylic resin which can be usedin the present invention is sold by DuPont under the trademark Pyralux™.A polyimide resin sold by DuPont under the name Kapton™ is anothersuitable alternative. Other good adhesive layer materials have beenidentified by Hutchinson Technology Incorporated which is located inHutchinson, Minn.

[0130]FIGS. 5B and 5C illustrate another feature of the invention whichmay be employed to provide vibrational damping in addition to anydamping effect which may be achieved by resin layer 95 which issandwiched between conducting and stiffening layers. In FIG. 5B, adamping layer 112 is continuously sandwiched between stiffener 88 and aconstraining layer 114, which, for example, may be stainless steel.Although it is possible to use a damping layer without a constraininglayer, better results are obtained when the damping material issandwiched between more rigid solids. This is because the damping effectrelies on the absorption of shear energy in the damping layer. Theamount of shear energy produced from vibrational motion of the flexure,and subsequently absorbed by the damping layer, is increased by using aconstraining layer. FIG. 5C is the same as FIG. 5B except that it showsthat damping layer 116 may be applied on the bottom side of the flexure,where it is sandwiched between conductors 72 and 74, and constraininglayer 118. As shown in FIG. 5C, damping layer 116 spans gap 75 betweenconductors 72 and 74. However, it is also possible for damping layer 116to be omitted in the region of gap 75, analogous to adhesive layer 95.Conversely, it is possible for adhesive layer 95 continuously to spangap 75 between conductors 72 and 74. A material known as ISD110™ orISD112™, available from 3M Corporation, is suitable for damping layers112 and 116.

[0131]FIG. 6 shows a side view of hinge region 89 of flexure 70.Proximal stiffener 80 and distal stiffener 88 flank hinge region 89.Resin layer 95 extends continuously in the region where stiffeners 80and 88 overlay conductors 72 and 74. Further considering some of thefeatures which characterize hinge or hinge region 89, within theelongate body of flexure 70, the hinge region can be thought of ashaving longitudinal boundaries which are indicated in FIG. 6 by dash-dotlines 89 a, 89 b. The conductor material which makes up hinge region 89is homogeneous (outside of these two longitudinal boundaries) only withmaterial which lies bounded between common (shared) spaced facial planeswhich intersect the regions of boundaries 89 a, 89 b. These two commonfacial planes are illustrated by dash-dot lines 73 a, 73 b in FIG. 6.Another way of viewing this is that the material in hinge region 89 ishomogeneous, beyond boundaries 89 a, 89 b, only with extensions of theconductor material itself which makes up the hinge region.

[0132]FIG. 7 schematically illustrates change in adhesive conformationdue to flexure deflection. By selecting an appropriate type of resin,and by controlling the amount used, it is possible to vary the degree ofstiffening obtained in the stiffened region. The type and amount ofresin 95 can also be selected to provide an advantageous vibrationaldamping effect. Resins typically exhibit varying degrees of elasticity.In FIG. 7, rectangular resin section 132 is stretched into trapezoidalresin section 134 when the flexure is bent. A greater degree ofstiffening is therefore achieved by selecting a resin which isrelatively unyielding or resistant to stretching.

[0133]FIGS. 8 and 9 illustrate views of a modified flexure, which inmany respects is the same as the flexure shown in FIGS. 2 and 3A. Animportant difference, however, is that in the flexure shown in FIGS. 8and 9, four conductors are provided in the conductive layer. It issometimes necessary to provide more than two conductors to the distalend of the flexure. For example, in transducer/flexure structures whichinclude a magnetoresistive read substructure, at least four conductorsare required. FIGS. 8 and 9 illustrate that the concept of the presentinvention, characterized by multiple load-bearing conductors, mayencompass designs which include many more than two conductors, eventhough most of the flexures specifically described in this applicationinclude only two load-bearing conductors.

[0134] In FIG. 8, a flexure 140 includes a stiffener 142 and a stiffener144 overlaying load-bearing conductors 146, 148, 150 and 152. As in thepreviously described design, although not shown in FIG. 8, thestiffeners are bound to the conductors by an insulative adhesive resin.Transducer chip 154 is directly bonded to the bottom side of conductors146, 148, 150 and 152, substantially as shown in FIG. 3B. A single wearpad is provided on the bottom side of chip 154 near the center of itstrailing edge. FIG. 9 shows the outline of the conductors in dashedlines. Note that in this structure, the conductors are distributedsymmetrically with respect to an imaginary plane which bisects theflexure along its length.

[0135] Turning attention now away from non-gimbaled structures made inaccordance with the teachings of this invention toward gimbaledstructures, it is important to note that gimbaled-type structures arefundamentally different from the flexure/transducer structures whichhave been described so far above. They are different in that gimbalmechanism allows the transducer chip ranges of pitch and roll motionindependent from the supporting flexure body. Gimbaling movement of atransducer chip has been recognized as an extremely important mechanicalfeature with respect both to flying structures and to contact-capablestructures. In the non-gimbaled flexures described above, the conductorshave been characterized as “load-bearing” structures because of therelative size and configuration in a proximal hinge region andthroughout the body or length of the flexure. In the descriptions whichnow immediately follow, gimbal flexures are described in which theconductors fulfill additional mechanical load-bearing and articulatingfunctions, such as hinge and torsional flexibility for adistally-located gimbal which permits pitch and roll movement of thetransducer chip relative to the flexure body. These gimbaledconfigurations are illustrated collectively in FIGS. 13-30, inclusive,and in each of the designs therein illustrated, the conductorscontribute functionally in at least three important ways: (1) to conductelectrical signals between a transducer and external circuitry; (2) tobear all or a portion of the deflected cantilever load, at least at somepoint along the length of the flexure; and (3) to provide a gimbalplatform (a transducer-carrying platform) for mounting a transducerchip. Accordingly, the embodiments that are shown in the collection offigures just mentioned are referred to as “conductor gimbalingflexures”.

[0136] A further matter to note is that in all of the flexure/transducerstructures which are described and discussed in this specification,there exists, fundamentally, a three-layer flexure structure to whichthere is attached or joined, in various ways, a transducer chip. Thethree layers in each flexure structure include a conductor layer, anadhesive layer, and a stiffener layer, and in each of these layers, andin the different embodiments, the specific configurations of thecomponents in the layer are somewhat different. Relying on the fact thatall now-to-be-described flexure/transducer assemblies have, in manyrespects, similar organizational characteristics, descriptions of theseembodiments will be presented in a more conversational flow ofstructural and functional qualities, rather than with a mechanisticlisting of parts followed by a functional description, and with aneffort to focus principally, and inter alia, on key differences thatdifferentiate the different embodiments.

[0137] Thus, and turning attention first of all now to FIGS. 10, 11,12A, 12B and 12C, here there is illustrated an embodiment of theinvention which employs what is referred to as a “load-button” gimbal.This embodiment closely resembles a head/flexure design previouslydisclosed and claimed in co-pending U.S. application Ser. No.07/783,619. Here a transducer/flexure 160 is principally supported byload-bearing conductors 162 and 164. At the distal end of conductors 162and 164 are articulator “ribbons” 166 a and 166 b on which a transducerchip 168 is mounted. A load button 170 is provided on the top side ofchip 168 around which rocking, inclinational movement of the chip isallowed. It is important to note, however, that the load button couldalso be provided on the bottom side of stiffener 180 for example, bycreating a downwardly protruding dimple. The height of load button 170is approximately equal to the thickness (0.5-mils) of conductors 162 and164 plus the thickness of adhesive layers 174 and 176. Adhesive layers174 and 176 facilitate lamination of stiffeners 178 and 180 on top ofconductors 162 and 164. FIG. 11 shows assembled flexure 160 withdetached transducer chip 168. FIG. 12A shows the top view of assembledflexure 160.

[0138]FIG. 12B illustrates the mounting configuration of transducer 168on flexure 160. In the region of flexure 160 where transducer 168 isattached, stiffener 180 is separated from conductor ribbon 166 b by air.As shown in FIG. 10, adhesive layer 176 only extends distally to thepoint where ribbons 166 a and 166 b begin. Transducer 168 is bonded bysolder structure 188 a and 188 b to conductor ribbon 166 b. The bottomside of transducer 168 has three wear pads 190 a, 190 b and 190 c (seeparticularly FIG. 12C) which contact the disk surface in a triangular(tripodic) pattern when the transducer is operating. Ideally, sufficientload is applied to flexure to maintain contact between each of the padsand the disk surface at all times.

[0139] In FIG. 13, flexure 200 includes conductors 202 and 204 which arespaced apart from each other and extend along the entire length offlexure 200. A gimbal structure or region 206 of the conductors islocated near the distal ends of the conductors. Each conductorcontributes one of a pair of parallel platforms (or articulatedportions) 208 a and 208 b which are located centrally within a cut-outgimbal region and serve collectively as a mounting platform fortransducer chip 210. This mounting platform is located adjacent what isalso referred to herein as the transducer unit receiving end of flexure200. Platforms 208 a, 208 b are also referred to as paddle portions.Stiffeners 212 and 214 are laminated, via adhesive as previouslydescribed, onto the tops of conductors 202 and 204 on opposite sides ofgap 213 which defines a hinge region. The stiffeners rigidify portionsof conductors 202 and 204 outside of hinge region 213. Additionally, thestiffeners' continuity from side-to-side provides structural compliancebetween the two load-bearing conductors 202 and 204. In gimbal region218 toward the distal end of stiffener 214, two additional stiffeners220 and 222 are laminated above the gimbal region 206 of conductors 202and 204. Stiffeners 220 and 222 serve to coordinate correspondingconductor regions and to isolate mechanical articulating conductors,i.e., conductive torsional beams, which will be shown and discussed inmore detail below.

[0140]FIG. 14 shows a magnified top view of gimbal region 206 ofconductors 202 and 204. Conductors 202 and 204 are distinctively shadedto assist the viewer in understanding the mechanical relationship andelectrical isolation of the conductors. Platforms 208 a and 208 b arecoordinated and jointly stiffened on the top side by stiffener 222. Onthe bottom side of platforms 208 a and 208 b, transducer chip 210 isattached. It is apparent that platforms 208 a and 208 b also function aselectrically distinct leads to transducer 210. Torsional beams(articulators, units, elements) 230 a and 230 b allow platforms 208 aand 208 b a limited range of pitch flexibility. Similarly, torsionalbeams (articulators, units, elements) 232 a and 232 b allow platforms208 a and 208 b a limited range of roll flexibility. Beams 230 a, 230 b,232 a, 232 b, collectively, constitute articulator structure which isreferred to herein as being characterized by mechanical and electricalhomogeneity—i.e., merged functionality. The gimbaling motion permittedby the torsional beams makes possible accommodation of angular ortopographic irregularities on the surface of a rigid medium. Althoughthe surface of a medium is ideally flat, in reality, irregularities dueto, for example, micro-roughness, polishing/texturing scratches, diskwaviness and/or “cupping”, non-parallelism of the spindle and actuatoraxes, and non-squareness of either of these axes and the disk surface,are inherently present to some degree. The torsional beams also permitthe head/flexure to accommodate static mounting tolerances.

[0141]FIG. 15A shows a top view of the flexure shown in FIG. 13, afterassembly. In FIG. 15A portions of conductors 202 and 204 can be seen inhinge region 244 and through window 242 which allows electrical bondingthrough the top side of flexure 200. Stiffener 212 also has hole 240concentrically located above conductor hole 241. Holes 240 and 241 areused for positioning the suspension on a mounting surface. Near thedistal end of flexure 200, gaps between stiffeners 220 and 222 defineflexible torsional beam portions of conductors 202 and 204.

[0142] An important feature of all the gimbaled flexures described inthis application is the configuration of pads (the three contact pads)located on the bottom side of the transducer chip for contacting thesurface of the recording medium during read/write operation. Unlike thenon-gimbaled flexures, a fundamental objective in the gimbaled designsis to maintain a parallel relationship (zero-angle-of-attack) betweenthe plane of the transducer chip and the surface of the recordingmedium. For this purpose, a load force is applied, via the deflectedflexure, urging the transducer chip into load-bearing contact with thedisk's surface. Multiple pad contact points on the bottom of thetransducer chip define a plane of interfacial contact between the chipand the disk. Ideally, torsional beams and/or hinges, load buttons, etc.permit the interfacial contact plane between the disk and the pads toremain intact, despite mounting tolerances and disk surface aberrations,throughout normal read/write system operation. The most common padconfiguration employed in the gimbaling flexures of the presentinvention, consists of a triangular arrangement of three pads, onelocated in the center of the trailing (or distal) edge of the transducerchip, and the other two pads being located at opposite front corners ofthe chip. The pole, which is contained typically in the trailing pad, ispreferably in constant contact with the surface of the media for themost high-level read/write performance. While this is a typicalarrangement, a reverse kind of arrangement is possible, and may offercertain performance advantages in selected applications. Moreparticularly, the central, pole-containing pad could be located adjacentthe leading edge of the chip. With this type of arrangement, relativemotion between the chip and disk tends to drive the leading-edgepole-containing pad into even more intimate working confrontation to therecording surface in a medium. Further, it is possible that polestructures might be provided in two, or in all three, of the pads.

[0143] Maximum stability is achieved when the pads are located as farapart as possible, consistent with chip size and disk flatnessconstraints. During pad-disk contact, the pads may be perturbed in the Zdirection by hitting pits or asperities in the surface. When thisoccurs, the downward load must be great enough to restore contactquickly between the pads and the disk. Pad size and shape is notcritical except that it is desirable to have the pad that contains thepole be as small as possible to minimize spacing loss, inasmuch as theactual contact point on the pad varies due to disk waviness. For wearreasons, it may be desirable to have larger pads which can sustainlarger removed wear volumes. Pads that become too large may create anair-bearing surface that causes a contact-intended transducer to flyrather than to slide. In addition, larger pads may exhibit higheradhesion forces, and consequently additional friction and stictionduring operation. Round pads may be desirable so that debris will notcollect on a flat leading edge, as has been observed in some cases onsquare or rectangular pads.

[0144]FIGS. 15B and 15C illustrate the pad configuration used on thebottom side of transducer chip 210. Stiffener 214 is laminated, viaadhesive 247, to conductor 202. Conductor 202 is electrically andmechanically attached to the top side of transducer chip 210 byload-bearing solder structures 248 a and 248 b. The chip may also beattached to the conductors by processes employing brazing or conductiveepoxy materials. As shown in FIG. 15C, pads 250 a, 250 b and 250 c arearranged in a maximally separated triangular configuration on the bottomside of transducer chip 210.

[0145] A large number of possible pad configurations may be employed inthe gimbal structures of the present invention. It is generallypreferred to use not more than three pads because four or more contactpoints create the possibility for rocking of the chip on the disksurface. It is possible for all three pads to be directly connected tothe transducer chip, or alternatively, as described in detail below, oneor more of the pads may be located on other parts of the flexure whicharticulate relative to the transducer-carrying portion of the flexure.In most of the gimbal structures described in this application, thepole-containing pad is located on the trailing edge of the chip body.However, as shown by the arrow in FIG. 15C, and as was mentionedearlier, it is possible, and sometimes preferable, to position thepole-containing pad on the leading edge of the chip (by rotating thechip 180°, or by reversing the direction of disk rotation). We havediscovered that the pad(s) which is positioned on the leading edge ofthe chip experiences a significant amount of friction with the disksurface, causing an unloading affect on the pad or pads located on thetrailing edge of the chip. This phenomenon must be taken into accountwhen deciding where to position pitch articulators in a gimbal. Further,we have found that electromagnetic signal performance can varysignificantly depending on whether the pole-containing pad is on theleading edge or on the trailing edge of the chip body. In general, wehave observed a significant increase in signal magnitude when the poleis positioned on the leading edge (instead of on the trailing edge) ofthe chip.

[0146] In a tri-pad arrangement of the type shown in FIG. 15C, where thetransducer chip is mounted on a gimbal permitting all three pads tocontact the surface of the medium continuously during normal operation,the transducer chip remains in a substantially parallel orientation,i.e., at a zero-angle-of-attack, relative to the surface of a disk. Thisfeature of the disclosed gimbal structures, represents a major departurefrom prior transducers/flexures which exhibit substantialangles-of-attack relative to a disk's surface. Positioning thetransducer chip to operate at a zero-angle-of-attack relative to thedisk surface provides the capability of employing a transducer designwhich, due to a particular coil structure, requires the main polestructure to be located inward from the transducer chip's trailing edge.

[0147] For example, as illustrated in FIGS. 15D and 15E, it is sometimesdesirable to locate a pad containing the main pole, inward from thetrailing edge of the chip. Flexure/transducer 251 is supported by beam252. Transducer chip, or chip body, 253, which is generally quite thinand planar, is mounted on the bottom side of beam 252. Projectingtri-pads 254 a, 254 b and 254 c are located on the bottom side of body253, defining a plane of interfacial contact between the transducer andthe disk's surface 256. Inductively coupled to the pole structure is agenerally planarly distributed coil, or coil structure, which lies inthe plane of chip body 253 in a coil region 255 generally designated bydashed lines in body 253. As shown, it is sometimes desirable to employa coil design which extends forward and backward from pole 254 a alongthe Y axis. In such a design, it is necessary to position thepole-containing pad inward from the trailing edge of the chip. Thisdesign goal is problematic, i.e., sometimes impossible, in aflexure/transducer which positions the chip with a significantangle-of-attack relative to a disk's surface. This is because, as thepole is moved inward from the trailing edge of a chip body, which isoriented with a significant angle-of-attack, it becomes impossible forthe pole to contact the disk. The distance between the pole and the diskbecomes greater and greater as the distance between the pole and thetrailing edge increases. Accordingly, the flexibility for implementingalternative pole and coil designs in transducers which operate at asignificant angle-of-attack is quite limited. It is important to notethat the positioning of pitch and roll articulators in a given gimbalconfiguration is primarily determined by the locations of the contactpads. For example, as the pole-containing pad is moved inward from thetrailing edge of the chip body, pitch articulators in the gimbal mustalso be moved in the same direction in order to maintain the desiredgimbal performance and load allocation among the pads.

[0148] In contrast, by providing a flexure/gimbal structure, which iscapable of supporting a transducer chip in parallel orientation(zero-angle-of-attack) relative to a disk's surface, a great improvementin transducer design flexibility is made possible. In the flexure/gimbalstructures of the present invention, the pole-containing pad may belocated practically anywhere on the working side or surface of the chipwithout altering the operable spacing (or contact relationship) betweenthe pole and the disk surface. The entire planar body of the transducerchip is available for containing coupled pole structure and coilstructure.

[0149]FIG. 16 is a thin-layer section including the pitch-accommodatingtorsional beams of the flexure shown in FIG. 15. The structures oftorsional beams 230 a and 230 b are analogous to conductor hinge 89 inFIG. 6.

[0150]FIGS. 17A and 17B illustrate a portion of a conductor gimbalingflexure which in all respects is the same as the flexure shown in FIGS.13-16, except that an additional damping layer is added. In FIG. 17A,damping layer 260 covers substantially the entire gimbal. Damping layer260 may be, for example, an elastomer available from 3M under thetrademark ISD110™ or ISD112™. The material is preferably diluted withethylacetate to 10% (V/V) of its original concentration, and thenapplied to the top of the flexure in the gimbal region as shown in FIG.17A. Use of such a membrane layer results in significant vibrationaldamping. It is believed that shear energy is absorbed by the membrane,particularly in regions of the gimbal where the maximum amount ofvibrational movement is expected to occur. A thin membrane can beemployed for this purpose without significantly stiffening the pitch androll motions otherwise permitted by the gimbal. However, to minimizefurther any stiffening effect of the membrane on the gimbal, and as isshown in FIG. 17B, a modified damping membrane configuration includesfour discrete membranes, or membrane patches, 262 a, 262 b, 264 a and264 b, each of which bridges two separate conductor portions in an areawhere the greatest degree of relative movement between the portions isexpected to occur. It is preferable to select a damping material whichexhibits a relatively high degree of elasticity under static conditions,and a high degree of stiffness when subjected to a high-frequencycondition.

[0151] Another desirable way of employing a damping membrane, such asthe ones illustrated in FIGS. 17A and 17B, is to position the dampingmembrane between either stiffener and conductor, or the flexure and anadditional constraining layer. Ideally, the adhesive layer, which isalready required in each of the laminant flexures described herein, andwhich can furnish damping action, may extend continuously through thegimbal region. The adhesive layer may extend through all of the gapsbetween stiffeners 214, 220 and 222 in the gimbal region. Alternatively,and in order to minimize any stiffening effect of the membrane on thegimbal, the adhesive layer may bridge gaps between stiffeners only indiscrete regions where maximum movement between the stiffeners isexpected to occur, similar to the configuration shown in FIG. 17B.

[0152]FIG. 18 shows another embodiment of a gimbaled transducer/flexurewhich employs a membrane interconnecting a flexure body and a transducerchip. In the structure shown in FIG. 18, the membrane functionsprimarily as a gimbaling structure and possibly also a damping layer.Transducer/flexure 270 includes a flexure frame portion 271 from whichtrace conductors 272 a and 272 b extend to transducer chip 273. Threecontact pads 274 a, 274 b and 274 c (dashed lines) are located on thebottom (working) side of transducer chip 273. The transducer pole (notshown) is preferably located in contact pad 274 a. In this design, traceconductors 272 a and 272 b are downsized (compared to previouslydescribed conductors) and shaped (folded or curved) so as to make theconductors insignificant structural contributors in thetransducer/gimbal region. Elastomeric membrane 276 spans the gap regionbetween flexure frame portion 271 and transducer chip 273. As alreadydescribed with reference to FIGS. 17A and 17B, a membraneinterconnecting a flexure frame and a transducer chip can be employedadvantageously for the purpose of damping vibrations. However, theprimary function performed by membrane 276 is to bear the cantileverload while permitting ranges of pitch and roll movement of transducerchip 273. Membrane layer 276 is the only significant load-bearingconnection between frame portion 271 and transducer chip 273. Byselecting the appropriate type, thickness and configuration, membrane276 may function as a gimbal structure to allow pitch and roll movementof transducer chip 273 independent from flexure frame portion 271, whilepossibly also damping vibrations. Membrane 276 is preferably sandwichedbetween flexure frame subportions and/or conductors.

[0153]FIGS. 19A, 19B and 20 illustrate a flexure which is similar to theone illustrated in FIGS. 13-16 except for several important differences.As shown in FIG. 19A, flexure 280 has two hinges 281 and 282. Hinge 281is characterized by a cut-out window in stiffener 283 near its proximalend exposing relatively thin conductors 284 and 286. The outlines ofconductors 284 and 286 underneath the stiffeners are shown in dashedlines. It is apparent that, although the reduced dimensions ofconductors 284 and 286 in the proximal hinge region (relative to thedimensions of previously described conductors) diminishes theload-bearing function of the conductors in that region, in theintermediate region of the flexure the conductors are wider, andtherefore carry a significant portion of the load. The configuration ofmodified hinge 280 results in a higher spring constant for accommodatinghigher loads in comparison to the loads carried by previously describedflexures.

[0154] The configuration of hinge 282 near the distal end of the flexureis similar to previously described hinges in that conductors 284 and 286are the sole load-bearing structures in that region. Gimbal 288 allowspitch and roll movement of stiffened transducer-carrying platform 289.Similar to the gimbal shown in FIGS. 13-15, gimbal 288 employs torsionalbeams 290 a and 290 b to allow roll movement of platform 289 independentfrom the body of flexure 280. Pitch movement is facilitated by hinges(articulators, units, elements) 292 a and 292 b which are rearwardlydisplaced from the center of the platform in order to equalize loaddistribution among the three medium-contacting pads (not shown). The useof hinges instead of torsional beams provides the important advantage ofincreased longitudinal and yaw stiffness. Another advantage of usinghinges to provide pitch movement instead of torsional beams is thatoverall width of the flexure in the gimbal region can be reduced. Thepitch-permissive hinges also provide a platform for dispensing adhesive.The configuration of conductors 284 and 286 in gimbal region 288 offlexure 280 is shown in FIG. 19B. Conductor 286 enters the gimbalmechanism through roll-permissive torsional beam 290 a, and enters thetransducer-carrying region through pitch-permissive conductor/hinge 292a to end in transducer-carrying semi-platform 293 a. Similarly,conductor 284 enters the gimbal mechanism through roll-permissivetorsional beam 290 b, and enters the transducer-carrying region throughpitch-permissive conductor hinge 292 b to end in transducer-carryingsemi-platform 293 b.

[0155]FIG. 20 shows a side view of flexure 280 operating on disk 295.Most of the bending which results from deflection of the flexure occursin hinges 281 and 282. Gimbal 288 mounts and supports transducer chip296. A “tri-pad” configuration (only two pads 297 a and 297 b areshown), as previously described, exists for maintaining an interfacialcontact plane between chip 296 and the surface of disk 295.

[0156] Flexure 300, as shown in FIG. 21, is the same as flexure 280shown in FIG. 19, except that the dimensions of conductors 302 and 304in region I are modified, and that flexure 300 is pre-bent in proximalhinge region 306 (FIG. 22A). This prebend exists along an axis 306 a(see FIG. 21) which defines a preferential bending axis for flexure 360.

[0157] Stiffener layers 301 a, 301 b, 301 c and 301 d are laminated ontop of conductors 302 and 304. The lateral dimensions of conductors 302and 304 in region I are shown in dashed lines because the conductors arecovered by stiffener 301 a. The reduction of conductor width in region Ican result in a significant reduction in capacitance levels.

[0158] The conductors can be made of different materials. However, anumber of factors must be considered when selecting an appropriateconductor material. In addition to being able to conduct electricity,the conductor material must exhibit appropriate physical/mechanicalproperties within the geometric and dimensional limitations whichdictate the operation and overall size of the flexure. When theconductors function as the only load-bearing components of the proximalhinge, as in previously described designs, it is preferable to usematerials, such as stainless steel, which have a relatively high elastic(Young's) modulus resulting in higher modal frequencies, and hightensible strength which can therefore support higher loads. However, inflexures such as the ones shown in FIGS. 19-22B, where the conductorsare relatively insignificant load-bearing components in the proximalhinge, beryllium copper is a suitable choice of material. With someconductor materials, such as stainless steel, it is preferable togold-plate the entire surface for at least two reasons. First,gold-plating in the bonding regions facilitates a solder connection.Second, gold-plating the entire stainless steel beam reduces resistance.When beryllium copper is used as the conductor material, it is onlynecessary to gold-plate the bonding regions.

[0159]FIG. 22A shows flexure 300 in its unloaded position U (solidlines) and in its loaded position L (dash-dot lines) relative to disk310. By pre-bending flexure 300 in hinge region 306 (on axis 306 a),flexure mount 312 can be parallel to the disk surface, thereby,minimizing disk-to-disk spacing.

[0160]FIG. 22B illustrates a modification of flexure 300 which involvesthe use of gimbal-motion-limiting guides, or “bumpers”, for the purposeof avoiding extreme, potentially catastrophic movement of gimbal partsout of the plane of flexure 300 in the case of a relatively high-shocksituation. Read/write systems are sometimes subjected to high-shockforces, for example, when a system is dropped or moved abruptly. In thissituation, gimbal parts which are connected by relatively small hingesor torsional beams, may be moved, bent or broken permanently away fromtheir operable positions. Accordingly, the modification of flexure 300shown in FIG. 22B, provides motion-limiting bumpers for preventingextreme movement of the gimbal parts with respect to the flexure bodyand to each other. In FIG. 22B, flexure 300 includes conductors 302 and304, the configuration of which has already been discussed referring toFIGS. 19A through 22A. Stiffeners 312 a, 312 b, 312 c and 312 d arelaminated on top of conductors 302 and 304. Stiffeners 312 b, 312 c and312 d differ from previously described stiffeners in that they includetabs which extend over air gaps between gimbal parts. These tabspartially cover (but do not touch) exposed conductor regions in anadjacent gimbal part. For example, tabs 314 a, 314 b, 314 c and 314 dextend over conductor edge regions of gimbal part 317. Bumpers 314 a,314 b, 314 c and 314 d significantly limit the extent to which gimbalpart 317 can move above the plane of flexure 300 in a high-shocksituation, while still allowing the desired range of roll torsionalmovement of the transducer chip independent from the body of flexure300. Similarly, tabs 316 a and 316 b are extensions of stiffener 312 c,protruding over conductor edge regions of transducer-carrying platform318. Bumpers, or tabs, 316 a and 316 b prevent extreme movement ofplatform 318 above the plane of gimbal part 317 or the body of flexure300, while still allowing the desired degree of pitch movement ofplatform 318 independent from the rest of flexure 300. Extreme movementof the gimbal parts below the body of flexure 300, can also be preventedby outwardly extending tabs 319 a, 319 b, 319 c and 319 d. Each of tabs319 a, 319 b, 319 c 319 d extend over a gap separating gimbal part 317from the body of flexure 300, and over an exposed conductor regiondefined by corresponding cut-outs in stiffener 312 b. It is apparent(although not shown) that similar outwardly extending tabs could beemployed to limit extreme movement of platform 318 below the plane ofgimbal part 317.

[0161] FIGS. 23-25 illustrate modified conductor gimbal configurationsemploying conducting articulators, namely, torsional beams, to allowlimited ranges of pitch and roll movement of a transducer platformindependent from a flexure body. Each of the gimbaling conductorstructures shown in FIGS. 23-25 can be implemented, with correspondingstiffeners, in flexures such as the ones shown in FIGS. 13-22B.Specifically, the gimbaling conductor structure shown in FIG. 14 couldbe replaced (along with appropriately modified stiffeners) with any oneof the structures shown in FIGS. 23-25.

[0162] In FIG. 23, gimbaling conductor configuration 320 is similar tothe one shown in FIG. 14, except that pitch-permissive torsional beams322 a and 322 b are located laterally and externally fromroll-permissive torsional beams 324 a and 324 b. In contrast to the FIG.14 configuration, where pitch-permissive torsional beams 230 a and 230 bconnect directly to transducer-carrying platforms 208 a and 208 b, inthe FIG. 23 configuration, roll-permissive torsional beams 324 a and 324b connect directly to transducer-carrying platforms 325 a and 325 b.

[0163]FIG. 24 illustrates the point that gimbaling conductorconfigurations may employ torsional beams which are obliquely angledrelative to lengthwise axis AX of the flexure. In gimbaling conductorconfiguration 330, the axes of external torsional beams 332 a and 332 b,and internal torsional beams 334 a and 334 b are each obliquely angledrelative to axis AX. The FIG. 24 configuration also illustrates thepoint that the torsional axes of torsional beam pairs, i.e., 332 a and332 b versus 334 a and 334 b, do not need to be perpendicular to eachother. These beams perform as mixed-mode articulators, with both hingingand torsional action.

[0164] In FIG. 25, the gimbaling conductor configuration is similar tothe FIG. 14 configuration, except for the addition of longitudinalstiffening arms 342 a and 342 b, each of which may be described as asimply supported cantilever with applied moment. Ideally, arms 342 a and342 b should connect with 344 a and 344 b, respectively, as close to thecenter of the gimbal as possible.

[0165] All of the gimbaling conductor configurations mentioned so far,embody a single pair of conductors. In contrast, FIG. 26 illustrates agimbaling conductor configuration with four conductors 352, 354, 356 and358. These form conductors are differently shaded in order to illustrateand clarify their respective paths from the flexure body into andthrough the gimbal. Each of conductors 352, 354, 356 and 358 contributestwo torsional beams and one quadrant of a transducer-carrying platform.For example, conductor 352 runs through torsional beam 352 a, thenthrough torsional beam 352 b and ends in transducer-carrying platformquadrant 352 c. Each of the other conductors follows a similarcomplementary path.

[0166]FIG. 26 also illustrates that the four right-angle torsional beamsshown in the FIG. 14 configuration can be replaced with four pairs ofbeams, wherein each pair includes two oblique beams. Each pair ofoblique beams, for example, the pair including beams 360 and 352 a, isreferred to as a “triangular, dual-beam torsional articulator”. Thetriangular dual-beam torsional articulator provides greater stiffness incomparison to the single right-angle beam systems previously described.It is also possible to produce a gimbaling conductor configuration inwhich torsional beams 360 and 352 a are parallel to each other.

[0167] The gimbaling conductor structure shown in FIG. 27A isfundamentally different from the previously described gimbals because,here, gimbaling movement is facilitated by hinges instead of bytorsional beams. In FIG. 27A, flexure 380 includes conductors 382 and384. Moving toward the distal ends of conductors 382 and 384,roll-permissive gimbal regions 386 and 388 are defined. Nearer thedistal ends, pitch-permissive hinge regions 390 and 392 are defined.FIG. 27B illustrates the distal end region of flexure 395 which includesthe gimbaling conductor structure 380 of FIG. 27A, with the addition oftop stiffening layers 394, 396 and 398. Stiffeners 394, 396 and 398stiffen all areas of the conductors except for isolated hinge regions386, 388, 390 and 392.

[0168] This hinging gimbal configuration provides several importantadvantages. First, it can be made smaller (less width required) comparedto the gimbal configurations which employ torsional beams, and thisallows more of the disk surface, at the inner diameter, to be used forrecording data since less pole-to-hub clearance is required. Second, aconsiderable amount of design flexibility is achieved withroll-permissive hinges 386 and 388 which can be positioned practicallyanywhere along the length of the flexure.

[0169] FIGS. 28A-30 illustrate another type of flexure which includeswhat may be thought of as a gimbal, but which differs from previousembodiments principally in that roll flexibility is achieved by theflexure body itself (i.e., by a “torsionally compliant beam”) ratherthan by torsional beams or hinges, as in previously described gimbals.Three torsionally compliant beams are illustrated. In FIGS. 28A and 28B,a torsionally compliant beam without a pitch gimbaling mechanism, isillustrated. In FIGS. 29A and 29B, a torsionally compliant beam isequipped with pitch-permissive torsional beams in the distal end of theflexure. In FIG. 30, a torsionally compliant beam with pitch-permissivehinges, is shown.

[0170] The first torsionally compliant beam, or flexure, described isshown in FIGS. 28A and 28B. Torsionally compliant flexure 400, from topview, includes three principal portions, namely, base portion 401, neckportion (also referred to as a “torsional compliance portion”) 402 andhead portion 403. In a preferred embodiment, base portion 401 has awidth W1 of 60-mils. Neck portion 402 has a width W2 of 20-mils. Headportion 403 has a width W3 of 40-mils. Conductors 404 a and 404 b(dashed lines in FIG. 28A) are adhesively bonded to overlying stiffeners405 a and 405 b. A hinge region 406 is defined by internal edges ofstiffeners of 405 a and 405 b. Three contact pads 407 a, 407 b and 407 care linearly arranged along the trailing edge of transducer chip 408which is bonded via solder structures 409 a and 409 b to the bottomsides of conductors 404 a and 404 b. Centrally located contact pad 407 bcontains the transducer pole. Only two of the three pads are necessaryfor the flexure to exhibit torsional compliance. For example, thecentral pad could be eliminated and the pole could be located in eitherone of the pads 407 a and 407 c. If the pole is located in one of theoff-center pads, it is preferable for the pole to be located in theoutside pad, i.e., the side of the chip which is closest to the outerperimeter of the disk, in order to maximize the amount of usable spaceon the disk. Alternatively, a pole can be located in each of the contactpads 407 a and 407 c. The two poles can be used alternately orselectively depending upon the particular situation. Flexure/transducer400 is shown with two conductors. However, it is apparent that a similartorsionally compliant flexure design employing four or more conductorscan be easily designed and fabricated.

[0171] A torsionally compliant beam must include the followinginterrelated features: (1) the neck portion of the beam must besufficiently torsionally soft to permit a desired range of roll movementof the head portion while maintaining sufficient lateral rigidity; (2)there must be at least two laterally-spaced contact pad pointsunderneath the head portion of the flexure; (3) there must be sufficientload applied to the head portion so that a line of interfacial contactbetween the contact pad points and the surface of the disk is maintaineddespite external irregularities or aberrations which cause torsionalflexing of the neck portion of the beam; and (4) the beam must exhibitsufficient lateral (anti-yaw) stability. Generally, as the distancebetween the laterally spaced contact points increases, less load isrequired in order to permit a desired degree of roll movement.Preferably, a torsionally compliant beam is sufficiently soft to permitplus or minus about 0.2° of roll under a total contact load of 300-mg.or less.

[0172] Note that flexure 400 is a gimbaling beam only in the sense thatit permits roll motion of the transducer chip. Flexure 400 does notinclude any pitch gimbaling mechanism. The torsionally compliant beamsillustrated in FIGS. 29A-30 are similar to flexure 400, except theyadditionally include pitch gimbaling mechanisms.

[0173] The second torsionally compliant beam illustrated is shown inFIGS. 29A and 29B. Flexure 410 includes load-bearing conductors 412 and414 which are separated from each other and extend the entire length ofthe flexure body. Importantly, the distal ends of conductors 412 and 414are configured cooperatively to provide pitch gimbaling. Parallel distalcentral regions 418 a and 418 b of conductors 412 and 414 form,collectively, a platform 418 for mounting transducer chip 419.Stiffeners 420, 422 and 424 are laminated by adhesive (not shown), tothe top sides of conductors 412 and 414. Stiffener 424, laminated to thetop side of platform 418, leaves exposed torsional beams 430 a and 430 bwhich allow a selected range of pitch gimbaling of transducer chip 419.A triangular configuration of pads is employed on the working side oftransducer chip 419. One pad is located near the center of the trailingedge of chip 419. The other two pads are located at opposite rearcorners of the leading edge of the chip. Similar to previously describedgimbal designs, the three pad configuration defines an interfacialcontact plane between the transducer chip and the surface of therecording medium.

[0174] Importantly, for a given selected material, intermediate neckportion 432 of flexure 410 is dimensioned (width, length and thickness)relative to the distance between laterally spaced contact pads on thebottom side of transducer chip 419, and the amount of load applied tochip 419, so that the neck portion is sufficiently torsionally soft toallow a desired range of roll movement of the transducer-carryingplatform, while maintaining the plane of interfacial contact between thecontact pads and the disk surface so that a desired range of torsionalflexibility (typically 0.2° to 2.0°) for the transducer-carryingplatform is permitted. Ideally, the beam is sufficiently torsionallysoft to allow the transducer chip to roll approximately plus or minusone degree from applied moment due to the load. For example, flexure 410has the following specifications: the load is approximately 300- to350-milligrams; the width of the neck portion 432 of the beam isapproximately 20-mils.; the length of the beam from proximal hinge toits distal tip is approximately 350-mils.; and the transducer chip 419is 40-mils. by 40-mils.

[0175] The flexure 440, shown in FIG. 30, is essentially the same astorsionally compliant beam 410, except that a pitch gimbaling movementis permitted by hinges 442 and 444 instead of by torsional beams.

[0176] FIGS. 31-34C illustrate another set of embodiments of theinvention, referred to as “dual-cantilever” flexures. In theseembodiments, also referred to as disk read/write structures, beams arestacked and spaced from each other by spacers located at each end. Theoverall dual-cantilever configuration may be referred to as a“parallelogram articulation substructure”. Analogous to a “four-barlinkage”, the flexure can be flexed without significantly altering theangular relationship between the transducer mounted on the distal endand the surface of a recording medium. Dual-cantilever flexure 460, asillustrated in FIG. 31, has two sets of conductors and four hinges.However, the dual-cantilever concept could also be implemented in aflexure with one pair of conductors and/or no hinges. Flexure 460includes a top layer of side-by-side spaced conductors 462 and 464 whichare laminated by adhesive, as previously described, to stiffeners 466,468 and 469, with gaps 470 a and 471 a defining proximal and distalhinge regions, respectively. Stiffeners 466 and 469 are mounted on topof spacers 472 and 474, which in turn are mounted on top of stiffeners476 and 477 on opposite sides of stiffener 478. Stiffener 476 isseparated from stiffener 478 by a gap 470 b which defines a secondproximal hinge region in addition to 470 a. Similarly, stiffener 478 and477 are separated by a gap 471 b which defines a second distal hingeregion in addition to 471 a. Stiffeners 476, 477 and 478 are laminatedon top of conductors 480 and 482. The distal ends of conductors 480 and482 support and are mounted on top of transducer chip 484. FIG. 32 showsa perspective view of flexure 460, assembled.

[0177]FIG. 33 shows the unloaded U (solid lines) and loaded L (dash-dotlines) positions of flexure 460 relative to disk 490. Note that flexure460 is pre-bent in its unloaded position, with most (ideally all) of thebending occurring in hinge regions 470 and 471. A notable feature of thedual-cantilever design is that equal and opposite bending occurs towardopposite ends of the flexure. Accordingly, as shown in FIG. 33,pre-bends in proximal hinge regions 470 a and 470 b are oppositelymatched by pre-bends in distal hinge regions 471 a and 471 b,respectively, so that transducer chip 484 maintains a parallelrelationship with disk 490 as it moves from its unloaded to its loadedposition. As shown in FIG. 33, by pre-bending a dual-cantilever flexure,an extremely close spacing between flexure mount 491 and disk 490 ispermitted.

[0178] FIGS. 34A-34C illustrate a modified dual-cantilever flexure whichdoes not have any stiffeners, hinges or pre-bends. Thus, it is apparentthat the dual-cantilever concept can be practiced beneficially in anunhinged (and non-pre-bent) flexure because one of the main reasons touse a proximal hinge, i.e., minimization of the angular constant of thedistal end, is substantially achieved by the dual-cantilever linkageitself. In FIG. 34A, flexure 500 includes top layer conductors 502 and504 mounted on top of spacers 506 and 508, on top of conductors 510 and512. It is necessary to provide electrical connection from the top layerconductors, for example, 502 and 504, to transducer 514 which is mountedon the bottom side of the distal ends of conductors 510 and 512. FIG.34B shows a perspective view of flexure 500, assembled.

[0179]FIG. 34C shows a side view of flexure 500 in its unloaded U(dash-dot lines) and loaded L (solid lines) positions, relative to disk518.

[0180] The dual-cantilever concept can also be embodied in flexuredesigns with more or less than four conductors. It is also possible toisolate all of the conductors in either of the top and bottom layers. Itis sometimes preferable to isolate all of the conductors in the bottomlayer because the distal ends of the bottom layer conductors are inbetter position for electrical connection to the transducer chip. Forexample, FIG. 35 shows a dual-cantilever transducer/flexure 520including top beam member 521 spaced from conductors 522 a and 522 b byspacers 523 a and 523 b located near the proximal and distal ends of theflexure, respectively. Transducer chip 524 is mounted on the bottomsides of the distal ends of conductors 522 a and 522 b.

[0181] Still another dual-cantilever embodiment 526, as shown in FIG.36A, includes two conductors 527 a and 527 b, each conductor extendingcontinuously over either the top or bottom layer of flexure 526. Nearthe proximal end of the beam, conductors 527 a and 527 b are separatedby spacer 528. A transducer chip 529 a is mounted to the distal end ofthe beam in an “on-end” or vertical orientation. As shown in FIG. 36B,chip 529 a is bound to conductors 527 a and 527 b by conductive epoxybonds 529 c and 529 d, thus eliminating the need for an additionalspacer at the distal end of the beam. Transducer chip 529 is mounted onthe bottom side of the distal end of conductor 527 b.

[0182]FIG. 37A illustrates a flexure mounting device which contacts andfollows the surface of the disk, thereby eliminating the need for apitch gimbal in the flexure. The device includes mount arm 532 attachedto pad 534 which contacts and follows the surface of relatively movingdisk 536. Flexure 538 is attached to mount arm 532, and supports, at itsdistal end, transducer chip 540 which contacts the surface of disk 536via contact pad 542. Assuming spacer pad 534 maintains contact with disk536, the height point 544 where the proximal end of flexure 538 ismounted, is maintained constant. By mounting flexure 538 on a mountingdevice which follows the contours of the disk, the need for pitchgimbaling is eliminated.

[0183] The transducer/flexure designs illustrated in FIGS. 37B and 37Crelate to the mounting structure shown in FIG. 37A in the sense thatcontact pads are located on separate structures which are allowed arange of articulation movement with respect to each other. Generally,this important feature of the invention makes possible gimbal designs inwhich the contact pads are spread out further from each other—resultingin greater surface accommodating stability. This is a contrast to thepad configurations previously described in which the distance betweenthe pads has been generally limited by the size of the transducer chip.

[0184] In FIG. 37B, transducer/flexure 545, near its distal end 546 a,has a hole 546 b for mounting, and a bonding window 546 c. A proximalhinge region 546 d exposes conductors 546 e and 546 f which are alsoexposed through bonding window 546 c. Moving toward the distal end oftransducer/flexure 545, in an intermediate region, stiffeners 546 g and546 h are laminated on top of conductors 546 d and 546 f, respectively.Conductors 546 e and 546 f are again exposed in a second hinge regiondefined by spaces between stiffeners 546 g, 546 h and stiffener 546 k.On the bottom side of the flexure portion stiffened by stiffener 546 k,contact pads 546 l and 546 m are positioned near opposite lateral edgesof the portion. Conductors 546 e and 546 f are again exposed in a thirdhinge region defined by a space between stiffener 546 k and stiffener546 p. Underneath and toward the distal end of stiffener 546 p,transducer 546 q is mounted. A contact pad 546 r is located on thebottom side of transducer 546 g, near its trailing edge.Transducer/flexure 545 can be viewed as being made up of plural,articulated beam portions.

[0185] In transducer/flexure 545, the conductors in the second hingeregion and laterally spaced contact pads 546 l and 546 m, collectivelyprovide for gimbaling movement of the transducer chip independent fromthe proximal end region of the flexure body. Pitch movement oftransducer chip 546 q is made possible by the conductor hinges in thethird hinge region between the laterally spaced contact pads and thecentrally located pad at the distal tip of the transducer chip.

[0186] The transducer/flexure shown in FIG. 37C is similar to the oneshown in FIG. 37B. Transducer/flexure 547, near its proximal end 548 a,has a hole 548 b for mounting alignment, and bonding windows 548 c and548 d. Conductors 548 e, 548 f, 548 g and 548 h are exposed in bondingwindows 548 c and 548 d, respectively, and in a first hinge region 549a. Moving distally along the flexure, stiffener 548 i is laminated ontop of conductors 548 e and 548 f, and stiffener 548 i is laminated ontop of conductors 548 g and 548 h. The conductors are again exposed in asecond hinge region 549 b which is defined by the spaces betweenstiffeners 548 i, 548 i and stiffener 548 k. On the bottom side of theflexure region stiffened by stiffener 548 k, are laterally spacedcontact pads 5481 and 548 m (shown in dashed lines). Continuing to movetoward the distal end of the flexure, the conductors are again exposedin a third hinge region 549 c, defined by the space between stiffener548 k and 548 n. At the distal end of the flexure, transducer chip 548 o(shown in dashed lines) is mounted on the bottom side of the flexure. Apole containing contact pad 548 p (shown in dashed lines) is located onthe bottom side of transducer chip 548 o.

[0187] Each of the embodiments shown in FIGS. 37A-37C, illustratesimportant modification options relating to contact pad configurations.First, these embodiments (FIGS. 37A-37C) show that the contact pads donot have to be formed on the chip itself, as they are in the previouslydescribed transducer/flexure designs. Second, it is possible to positionone or more of the contact pads on beam portions of the flexure whicharticulate independently from the flexure portion on which thetransducer is mounted. For example, in a gimbal such as the one shown inFIGS. 13-15C, the laterally-spaced contact pads on the leading edge ofchip 210 could be replaced on the bottom side of the roll framestiffened by stiffener 220. These principles make it possible toincrease greatly the longitudinal and lateral distances between the padswithin constraints due to size and disk waviness. As already noted,increasing the distances between the pads improves the operablestability of the flexure. Increase in the distance between the pads alsomakes it possible for the gimbal to perform under a lighter load.Minimizing the load, in turn, is important for the purpose of minimizingwear, reducing function, and lowering the probability of head and/ordisk crash events.

[0188] FIGS. 38A-38C illustrate two flexure mounting systems. Themounting system illustrated in FIGS. 38B and 38C employ adual-cantilever structure resulting in closer disk-to-disk spacing incomparison to previous flexure mounting systems, such as the oneillustrated in FIG. 38A. The flexure mounting system 550, shown in FIG.38A, includes E block 552 supporting flexure mounts 554 a, 554 b, 554 cand 554 d, which in turn hold flexures 556 a, 556 b, 556 c and 556 d,respectively. The flexures are supported in contacting relationship withopposing surfaces of disks 558 a and 558 b. Because of the relativelyrigid relationship between E block 552 and mounts 554 a-554 d, in orderto accommodate mounting and operating tolerances, a relative largespacing distance 560 must be maintained between the disks. In contrast,the flexure mounting system 570, as shown in FIG. 38B, permitssignificantly closer disk-to-disk spacing, by using a dual-cantilever inthe mounting structure. In flexure mounting system 570, E block 572supports dual-cantilever mounting structure 574 which has an elongatedistal end 576 connected to flexure 578, which end supports transducerchip 580 in contact with the surface of disk 582. Each of the otherflexures in the system shown in FIG. 38B, is similarly mounted.Dual-cantilever structure 574 allows relative movement between E block572 and disk 582, while maintaining a parallel relationship between itselongate distal end 576 and the surface of disk 582. Accordingly,requisite disk-to-disk spacing 584 is greatly reduced relative todisk-to-disk space 560 in the prior system illustrated in FIG. 38A.

[0189]FIG. 38C is a magnified view of a single flexure mounting devicefrom FIG. 38B. The elongate distal end 576 of dual-cantilever structure574 supports pad 586 in a contacting relationship with the surface ofdisk 582. The proximal end of flexure 578 is attached to dual-cantileverstructure distal end 576. By employing dual-cantilever structure 574 anddisk-contacting pad 586, dual-cantilever distal end 576 is maintained ina parallel relationship to the surface of disk 582, and at a constantheight above the disk. In addition to allowing closer disk-to-diskspacing, the design shown in FIG. 38C also substantially eliminates theneed for pitch gimbaling analogous to the system illustrated in FIG.37A.

[0190] Another aspect of the present invention relates to the goal ofsimplifying the process of mounting a flexure on an E block, and morespecifically, providing an easy way of connecting the flexureelectrically to a flex cable. FIGS. 39A-39C illustrate a flexuremounting structure which is versatile in the sense that it can be easilyelectrically connected to a mother flex cable in either an upside or adownside orientation. Nut-plate/flexure structure 587 a, as shown inFIG. 39A, includes a flexure 588 a which may take the form of any of theflexures previously described in this application, except for itsdifferent conductor structure. Nut-plate 588 b is welded by spots 588 cto a stiffener layer which is laminated on top of conductors 589 a and589 b toward the proximal end of flexure 588 a. Conductors 589 a and 589b run from the transducer chip through the flexure where conductor 589 apasses through the center region of the flexure and conductor 589 bextends along both sides of the intermediate portion of flexure 588 a.Conductor 589 b then passes under nut-plate 588 b, and eventuallyextends in opposite lateral directions along paths leading to laterallyopposite, proximally located tabs 588 aa and 588 bb. Similarly,centrally extending conductor 589 a extends under nut-plate 588 b andeventually splits into separate laterally opposite directions on pathswhich-end in tabs 588 aa and 588 bb. On tab 588 aa conductors 589 a and589 b are exposed on the bottom side, and therefore are not visible inthe view shown (dashed lines). Conversely, conductors 589 a and 589 bare exposed on the top side of tab 588 bb. Thus, if nut-plate/flexure587 a is mounted under an E block arm, electrical connection to the flexcable is accomplished by bending tab 588 bb up so that the conductorscontact the flex cable conductors. Alternatively, if nut-plate/flexure587 a is mounted on top of an E block arm, electrical connection isaccomplished by bending tab 588 aa down so that conductors 589 a and 589b contact the conductors in the flex cable. FIG. 39B shows fournut-plate/flexures, each one configured as shown in FIG. 39A, mounted onan E block. Nut-plate/flexure 587 a is electrically connected to a flexcable 588 d via conductor contact tab 589 bb. Nut-plate/flexure 587 b iselectrically connected to flex cable 588 d through conductor contact tab589 cc. Nut-plate/flexure 587 c is electrically connected to flex cable588 d through conductor contact tab 589 dd. Nut-plate/flexure 587 d iselectrically connected to flex cable 588 d through conductor contact tab589 ee.

[0191]FIG. 39C shows a modified conductor configuration that results inlateral tabs which facilitate easy upside/downside electrical connectionto a flex cable. Nut-plate/flexure 588 e includes conductors 589 i and589 i which extend from a gimbaled transducer mounted near the distalend of the flexure, through the flexure body, under the nut-plate, intosemi-circular conductor contact tab 589 ff then to conductor contact pad589 gg. On tab 589 ff, conductors 589 i and 589 j are upwardly exposed.On pad 589 gg, conductors 589 i and 589 i are downwardly exposed, andtherefore not visible in the view shown (dashed lines).

[0192] The flexures previously described are generally designed tooperate under a load in the range of 30- to 300-, and preferably 35- to70-milligrams. It is important to minimize the load exerted on theflexure during operation in order to minimize the rates of head and diskwear and to lower frictional power consumption. However, for thoseflexures which include a gimbal, it is necessary to apply a load whichis great enough to maintain contact between the transducer chip contactpads and the disk surface, through the desired ranges of pitch and rollmovement. It is generally possible to upsize and downsize the flexuredesigns described in this application, for use under different appliedloads. For example, the load which is required for adequate gimbaling ofa given flexure design, can be decreased by lengthening and/or thinningthe dimensions of gimbal articulator structures, i.e., hinges ortorsional beams.

[0193] FIGS. 40A-40C illustrate a flexure which is designed to operateunder a load of approximately 35- to 70-milligrams. Beginning near theproximal end of flexure 590, a hole 591 a is provided for mountingalignment. A window 591 b exposes conductors 592 a and 592 b forelectrical bonding. Within proximal hinge region 591 c, conductors 592 aand 592 b are again visible. The primary structural components of hingeregion 591 c are stiffener straps 591 d and 591 e which are integralparts of stiffener 591 f. Approaching the distal end of flexure 590,distal hinge region 591 g is made up of lateral edge portions ofconductors 592 a and 592 b. A gimbal 591 h is provided near the distalend of flexure 590 for mounting a transducer and for facilitatingmovement of the transducer independent from the main body of flexure590. Three separate stiffeners 591 i, 591 j and 591 k define gimbalarticulators which are shown in more detail in FIGS. 40B and 40C.Dimensions of flexure 590 are as follows:

[0194] AA=0.060-inches

[0195] BB=0.455-inches

[0196] CC=0.030-inches

[0197] DD=0.010-inches

[0198] EE=0.350-inches

[0199] FF=0.080-inches

[0200]FIG. 40B illustrates an isolated top view of the conductors 592 aand 592 b. The conductors are separately shaded in order to emphasizetheir separate paths. Stiffening layers 592 c and 592 d are co-planarwith conductors 592 a and 592 b, but are separate from the conductors sothey do not function as conductors in flexure 590. Conductor 592 aextends to the distal tip of flexure 590, then passes toward thetransducer chip through torsional beam 592 e, then through hinge 592 f,finally ending in a transducer mounting platform 592 g. Similarly,conductor 592 b passes through torsional beam 592 h, then through hinge592 i, and ends in a transducer mounting platform 592 j.

[0201]FIG. 40C shows a magnified view of the assembled gimbal in flexure590. As previously described, stiffeners 591 i, 591 i and 591 k exposeand define gimbal articulators, namely, roll-permissive torsional beams592 e and 592 h, and pitch-permissive hinges 592 f and 592 i.Shock-resistant tabs 594 a, 594 b, 594 c and 594 d extend across the gapbetween stiffeners 591 i and 591 k. These tabs limit the distance orextent to which the transducer-carrying central region of the gimbal canmove upward along the Z axis out of the plane containing the rollstructure stiffened by stiffener 591 j. Similarly, tabs 595 a, 595 b,595 c and 595 d extend across the gap between stiffeners 591 i and 591j, thereby limiting the extent to which the roll frame can move upwardalong the Z axis above the plane containing the main body of theflexure. The primary purpose of the tabs is to limit the movement ofgimbal parts in a high-shock situation.

[0202] Miniature reservoirs for containing dampening material in andaround the gimbal region are also defined. Each reservoir is typicallyformed by making semi-circular cuts on opposite edges of stiffeners neara gap between gimbal parts. For example, an outer organization ofreservoirs 597 a, 597 b, 597 c and 597 d facilitate deposition of adamping material through a syringe, for example, damping material 598 inreservoir 597 a, creating a bridge across the gap between stiffener 591i and 591 j. Two more damping material reservoirs 599 a and 599 b arelocated across gaps between stiffeners 591 j and 591 k on opposite sidesof stiffener 591 k. Hole 599 c in the center of stiffener 591 k isprovided to permit application of adhesive for the purpose of bondingthe chip to the suspension. Preferred dimensions in the gimbal regionare as follows:

[0203] GG=0.0028-inches

[0204] HH=0.007-inches

[0205] II=0.024-inches

[0206] JJ=0.002-inches

[0207] KK=0.020-inches

[0208] LL=0.040-inches

[0209] MM=0.002-inches

[0210] NN=0.002-inches

[0211] OO=0.002-inches

[0212] conductor thickness=0.0004-inches

[0213] stiffener thickness=0.0008-inches

[0214] It should be noted with respect to flexure 590, as well as all ofthe other flexures previously described in which a hinge is located nearthe distal end of the flexure, that it is sometimes preferred to replacethe hinge with a pre-bend. Such a bend is in the range of approximately1°-4° around an axis parallel to the X axis (rotation of the distal endof the flexure upward out of the plane containing the flexure body).Fabricating a bend near the distal tip of the flexure is an extramanufacturing step in comparison to a process for manufacturing a flatflexure with a proximal hinge. However, a proximal bend is sometimespreferred over a proximal hinge because it improves vibrationalstability and is more robust to shock. For example, FIG. 40D showsschematically a side view of flexure 599 d which includes a main bodyportion 599 e and a distal end portion 599 f. The distal end portion 599f is slightly bent at point 599 g with respect to main body portion 599e. Angle α, i.e., the degree of pre-bending is approximately 1-4°.

Methods of Production

[0215] Various combinations of machining and chemical etching steps maybe used to construct flexures of the present invention.

EXAMPLE 1

[0216] Multiple sets of flexure layers are cut out of single sheets. Forexample, FIG. 41 shows a sheet 600 with four quadrants 602, 604, 606 and608. A set of laminated flexures is produced simultaneously in eachquadrant. The following figures and description focus on only a singlequadrant.

[0217] A 1-mil. layer of stainless steel is mechanically (laser) cut outin the pattern shown in FIG. 42. Cut-out section 610 defines the hinge,and cut-outs such as 612 form rectangular windows for wire bonding.

[0218] A second sheet of adhesive is cut with the same pattern as shownin FIG. 42. If the adhesive is attached to the 1-mil. stainless steellayer prior to cutting, both layers can be cut simultaneously.

[0219] A conductive layer is mechanically cut out of a 0.5-mil. thickstainless steel sheet, according to the pattern 613 shown in FIG. 43, sothat all conductors are electrically isolated after the final cut ismade, as explained below. The material is then cleaned and gold platedon both sides of the sheet in region PP.

[0220] The alignment holes are then used to align the layers on toolingpins. The layers are pressed to specified loads and heated in an oven topromote curing of the adhesive.

[0221] The laminant is cut with a laser to define the beam shape 614 asshown in FIG. 44. The cut either defines individual beams 614 or “combs”616 of beams.

[0222]FIG. 45 shows a composite of all cuts.

[0223]FIG. 46 shows a final beam, essentially corresponding to theflexure illustrated in FIGS. 2 and 2B.

[0224] The flexure shown in FIG. 46 has the following dimensions:

[0225] A=40 mils.

[0226] B=20 mils.

[0227] C=350 mils.

[0228] D=390 mils.

[0229] E=430 mils.

[0230] F=24 mils.

[0231] G=10 mils.

[0232] H=12 mils.

[0233] I=21 mils.

[0234] J=44 mils.

[0235] K=60 mils.

EXAMPLE 2

[0236] The second manufacturing example employs chemical etching and/orlaser cutting steps. Three sets of conductive layers are cut out fromareas 330, 332 and 334 of one sheet 336, as shown in FIG. 47. Thefollowing description and drawings refer to the production of a singleset of flexures from area 330. Alternatively, a continuous sheet ofadhesive can be applied, then cut out by plasma etching after theconductor and stiffener layers are laminated.

[0237] A 0.5-mil. thick stainless steel conductor layer is patterned asshown in FIG. 48. Pattern 340 is cut out either by chemical etching orlaser cutting. During the production process, conductor pairs remainattached to adjacent conductor pairs by tabs 342. A corresponding 1-mil.thick stainless steel stiffener layer is chemically etched or laser cutaccording to pattern 343 shown in FIG. 49. Adjacent stiffeners are heldtogether by tabs 344 and 346. An adhesive layer is applied either bystamping or laser cutting.

[0238] A 0.5-mil. thick layer of gold is plated onto the conductors. Thegold may be plated onto the entire conductor surface (preferred forstainless steel) or may be confined to the electrical bonding regions(preferred for beryllium copper).

[0239] The layers are aligned and bonded under temperature and pressure.

[0240] Finally, individual flexures are separated from each other bymechanically shearing or laser cutting tabs 342, 344 and 346.

[0241] Other methods of producing laminant suspensions such as the onesdisclosed in U.S. Pat. No. 4,991,045 and No. 5,187,625 (both areincorporated here by reference) have been developed by HutchinsonTechnology Inc. of Hutchinson, Minn. and are generally applicable to theflexures disclosed in this application.

EXAMPLE 3

[0242] The following technique is used to attach the transducer chip.

[0243] Solder paste is applied with a stencil to the chip or beam(conductors).

[0244] The beam and the chip are aligned and the solder is heated to itsmelting point either locally with hot air, laser or infrared heating, orplaced in an oven.

EXAMPLE 4

[0245] Another method for attaching the transducer chip involves lasersoldering. First, tin is deposited on gold bonding pads on the chip.Second, a laser is used to heat the gold and tin through small holes(example, holes 90 in FIGS. 2 and 3A) in the metal (stiffener) or byheating the metal directly. The tin and gold melt to form a eutecticbond.

EXAMPLE 5

[0246] The following process is used to attach a damper for the purposeof attenuating vibrations. Damping material can be applied either beforeor after patterning.

[0247] In a pre-patterning technique, damper (viscoelastic polymer onconstraining layer) is stamped or cut with a laser to define the shape.Each damper is then aligned individually and then applied to each beam.

[0248] In a post-patterning process, a square of damping material withconstraining layer is applied to the beam or comb without precisealignment. A laser is then used to trim the shape of the dampingmaterial to be slightly larger than the beam shape.

EXAMPLE 6

[0249] The following techniques are used to lap a single pad on a chip,for example, 97 in FIGS. 3B and 3C.

[0250] First, the beams are made on a comb with relatively long fingers.The comb is placed in a “lapper/tester” machine which loads the beamonto a rough disk for lapping. Electrical connection is made through themetal in these fingers (an extension of the beam conductors).

[0251] The machine individually twists the comb fingers and uses themagnetic signal as a lapping stop indicator to achieve “roll” facets.

[0252] Pitch facets are achieved by changing the Z-height and therebychanging the angle at the beam tip.

[0253] Magnetic performance may also be tested in the process.

EXAMPLE 7

[0254] The following technique is used for lapping a three-pad chip,such as the one employed in the gimbaling flexures described above.Since the gimbal compensates for static tolerances, only a flat lap isrequired to achieve full signal quickly in the drive. Therefore, ashorter, simpler comb may be used with a simpler lapping machine. Thismachine loads the beams to a given Z-height, exposing the pole andtesting.

[0255] It is also possible to lap the chip pad prior to attaching thechip to the beam.

[0256]FIGS. 50A and 50B schematically illustrate modified forms oftransducer chips. In contrast to the rectangular transducer chipspreviously described, the chips shown in FIGS. 50A and 50B havedifferent shapes for the purposes of: (a) maximizing the lateral andlongitudinal distances between contact pads; (b) minimizing the weightof the transducer chip; and (c) maximizing the efficient use ofmaterials in the chip-making process. The T-shaped and triangle-shapedtransducers, as shown in FIGS. 50A and 50B, respectively, areparticularly useful chip designs where a tri-pad arrangement is formedon the bottom of the chip for use in a gimbaled, disk-contactingtransducer/flexure. In FIG. 50A, T-shaped chip 400 has contact pads 402a, 402 b and 402 c arranged in a triangular configuration. Similarly, inFIG. 50B, triangular chip 410 has three contact pads 412 a, 412 b and412 c, again arranged in a triangular configuration. The shapes anddimensions of the chip are also dictated by the particular coilstructure which is typically embedded in the chip.

[0257] Although numerous embodiments of the invention have beendescribed in detail above, it is apparent that many other modificationsare enabled by the disclosure and encompassed in spirit and scope by theclaims set forth below. For example, while most all of the embodimentsspecifically described above are transducer/flexures which are designedto operate in contact with the surface of a medium, it is apparent thatmany of the principles of the present invention have application tonon-contacting or quasi-contacting transducer/flexures, such as “flyingsliders”. Flying sliders do not employ pads such as the ones describedin this application, but instead employ rails or air-bearing pads.However, flying sliders frequently require gimbaling mechanisms, andface many similar mechanical accommodation challenges as do contactingtransducer/flexures. The fact that most of the embodiments described inthis application are shown with contacting pads, should not be viewed inany way as a limitation on the applicability of the present invention tonon-contacting or quasi-contacting head/flexure systems.

[0258] Further, it is important to recall that many of the features ofthe present invention can be employed to great advantage with mediumsother than rigid disks—for example, with drums, floppy disks, tape, etc.

We claim:
 1. A disk-drive flexure/conductor structure comprising anelongate flexure body having a distal end including a plurality ofconductors spaced from each other and extending along substantially theentire length of the body, and an electromagnetic transducer mounted onthe distal end of the flexure body and held in dynamic contact with arecording surface of a magnetic recording medium amid read/writecommunication with said medium, and wherein each of said conductors hasa thickness which is at least about 13% of the total thickness of thebody so that the conductors function as load bearing beams at leastpartially supporting the transducer.
 2. A device for storing andretrieving information on a spinning rigid disk comprising: a transducercomposed of a plurality of adjoining solid films including a disk-facingprojection, a conductive coil inductively coupled to a magneticallypermeable core terminating in a pair of tips encased by said projectionfor concurrent contact and communication with the disk, and an elongatedarm attached to said transducer, composed of a plurality of adjoiningsolid layers and having a length, a width and a thickness with saidthickness being substantially less than said width and said width beingsubstantially less than said length, said aim including a plurality ofconductive ribbons extending lengthwise, separated widthwise andconnected to said coil.
 3. The device of claim 2, wherein at least oneof said tips is exposed adjacent to the disk.
 4. The device of claim 2,wherein said conductive ribbons are disposed on a disk-facing portion ofsaid arm.
 5. The device of claim 2, wherein said conductive ribbons areseparated from other solid layers of said arm adjacent to saidtransducer.
 6. The disk-drive flexure/conductor structure of claim 2,wherein the thickness of the conductors are at least about 20% of thetotal thickness of the flexure body.
 7. The disk-drive flexure/conductorstructure of claim 2, wherein the flexure body has a proximal endopposite from the distal end, the flexure body having two lateral edgeswhich taper inward from the proximal end toward the distal end so thatthe width of the flexure body near the distal end is less than the widthof the flexure body near the proximal end.
 8. The disk-driveflexure/conductor structure of claim 1 further comprising a gimbalmechanism connecting the flexure body to the transducer so that thetransducer is permitted to move relative to the flexure body duringread/write operation on a magnetic recording medium.
 9. The disk-driveflexure/conductor structure of claim 1, wherein the flexure body has atleast one location along its length where the conductors are the soleload-bearing beams in the flexure body.
 10. The disk-driveflexure/conductor structure of claim 9, wherein said location along thelength of the flexure body defines a hinge region for permittingcontrolled movement of the transducer along a Z-axis perpendicular to arecording medium surface.
 11. The disk-drive flexure/conductor structureof claim 9, wherein said location is closer to the proximal end of theflexure body than it is to the distal end of the flexure body.
 12. Thedisk-drive flexure/conductor structure of claim 1 wherein the flexurebody includes at least one stiffening layer adhesively bonded to theconductors.
 13. The disk-drive flexure/conductor structure of claim 10,wherein the flexure body includes stiffening layers adhesively joined tothe conductors on opposite sides of the hinge region.